Interleave is all about read speed. You see, most of the time, the computer will read more than one sector. But when reading a sector, there is some overhead. Because the driver has to hand off data to the OS, advance its buffer pointers, decrement counters, stuff like that. So what happens is, the computer needs a little extra time in between each sector. This could be accomplished by just leaving larger gaps, but that would waste space. So, what you really do is, you change the order of the sectors on the track. Instead of storing 9 sectors as (1,2,3,4,5,6,7,8,9) and interleave of 2 will skip every other sector, arranging them like (1,6,2,7,3,8,4,9,5). That means, after reading sector one, the computer has time while sector 6 is moving past the drive head, and then it can read sector 2. Then again it can do "housekeeping" while sector 7 passes the drive head, and go on to read sector 3. Without interleave, a slow computer would have to wait a full rotation of the floppy until it could read the next sector, wasting a lot of time. The same technique was used on early harddisks. Since they were faster than floppies, the problem was even more impactful. And you could get better performance out of your disk if you determined the optimal interleave for your specific system. Because it depends on the speed of your system, the rotation of the disk and the controller, the optimal interleave has to be determined for each specific system. And it could be fine tuned to not miss a sector on sequential read, but not interleaving to much. Hope this helps.
Guess I should have read the comments before replying with a short but similar answer. Interleave way back when was a major issue with MFM and RLL hard drives. Too small and the drive would be crazy slow, too large and it would just not be as fast as possible. I recall using Gibson research Spinrite to calculate and adjust the interleave on old drives.
Interleave has to be increased to 2 for a 21 sector DMF, as there is just not enough space / time for the sector gaps, the drive just cannot synchronize the read... a bit like for very old HDD where the interleave was about 6 for a slow 8 bit controller, and down to 2 for an unbufferred 16 bit. The slip / skew options are powerful when used right. On an 18 or 20 sector, typically a skew factor of 3 on track, and 0 or 1 on head gives an improvement, as otherwise the drive will miss the next sector and waste a rotation on track stepping, while some drives may be able to switch the head fast enough. The sector alignment of DMF may already provide a skew factor. Also, one beware on T82 (more so if you risk T83 or T84). If the drive uses a lead screw mechanism, over-tracking can jam it... bumping the end stop on other mechanisms is not great for them, but not usually fatal. Secondly, if searching for the over tracking limit, or just using T82, use verify after format rather than the verify at the same time (which may be faster), otherwise it won't know that its overwriting the track while its endstopped
What is this floppy disk interleave thing anyways? I've literally reverse engineered the floppy disk formats in hex disk editors and never heard of any interleave factor. I've even made my own versions of Win311 that fit on a single floppy disk. Tried all formats including these, and get a very regular timed tick tick tick readback. Thought that interleave only applied to super early hard drives. Edit: I forget, I made sure my files loaded in order and had no fragmentation.
Interleave make the floppy slower for better performance on slower machines. It does not write the sectors sequentially, so e.g. 1, 9, 2, 10, 3, 11... for interleave=2 This halves the transfer rate because the drive has to rotate two times to read a track. So it is ideal to have a interleave that make the drive just a tiny bit slower than the max transfer rate of the machine. Otherwise the drive has to re-read sectors all the time totally tanking performance.
@@southernflatland Interleave affects the way you read a track sequentially. The floppy controller on some machines cannot read all sectors on a track in one rotation if they are in sequence /ie back-to-back), but read one sector, wait one rotation and read the next... on a standard floppy that means 18 rotations to read all sectors in sequence on a track. With interleave you mix them up, so you can read it faster, Basically interleave of 2 means it takes 2 rotations to read all the sectors of one track in sequence, with interleave of 3 it takes 3 rotations and so on.
@@southernflatlandinterleave will only be usful for older, slow machines/io/drives that cannot transfer the data per sector quick enough and so miss the start of the next sector. Skew is the same, slow, old, etc. This where you change tracks (move heads) and you miss the start of first sector of the next track.
@@recycledsteel3693 Oh I get you, I do. I'm familiar with the interleave/skew thing, just never heard of that for floppy disks. Makes me wonder what byte I missed in the hex decode of floppy disk FAT12 format.
OS/2 had roughly 100 back in the day. You could make them from the CD per batch file. Problem there was that this only worked until you hit a bad floppy and then you had to start the process all over again. Path of pain indeed.
man that took me back, thanks for that blast from the past! i still remember vividly performing my own experiments with fdformat 1.8 (and pkzip) as a little kid back in the day, so that i could maximize the amount of games i could squeeze onto my floppies, because my 386's 80 mb hard disk couldn't nearly hold them all. the performance drop, the reliability loss (which i didn't know at the time to be caused by the extra tracks) and the tsr requirement ultimately deterred me from storing my entire collection that way though, as it made zip files spanning multiple (no-name) disks way too risky. don't want to lose a classic like monkey island or doom (which was ofc either thumbnail-sized or a slideshow on my 386) to a bad outer track! later, that story kind of repeated with overburning and a more tightly wound groove on cds...
I remember formatting floppies to 1.68MB back in those days. It was neat to do, but rather unreliable for long-term storage. Also my first experience with Win95 back in those days was via 25 floppies. I got my hands on 95 beta build 359 and it fit on 25 normally formatted disks. Those were the days!
yeah I gave a copy of it to our IT department even when I was in college... told them I had the Win95 beta, and gave them a couple of boxes of floppies. I had to remind them after a couple of weeks of inaction that they weren't a GIFT so use it and give them back to me! They really dropped the ball on that one... but the Windoze lab head was one of their less enthusiastic people anyways. I was an official beta tester for Windows Powerstation Fortran, which got me the actual Windows 95 beta CDs as well long before release - showing people the Weezer video (often the first decent quality movie anybody had seen on their PC) and watching them drool was always fun. Less funny, installing a series of Win97 betas... and then they randomly renamed it to Win98 from one build to the next. :D
@@hewhohasnoidentity4377 yup, floppies were a step up from tape or punch card, but they seem seemed to fuck up often in crucial situations like handing in coursework
@@hewhohasnoidentity4377 floppy disks were very reliable, heck PCs in the 80s used floppies as boot disks, It's just that overtime the quality of each disk went down as the price went down, especially the 3.5" ones. The same thing happened to optical media, new CD-Rs and DVD-Rs are susceptible to burn failures compared to their older counterparts as they're made more cheaply.
Because of the original PCs being so slow, the inter-sector gap was long to account for timing inaccuracies when writing. With a computer such as the Amiga which always wrote an entire track rather than single sectors, the large gaps were not needed. This allowed for 11 sectors/track rather than only 9 for a double density disk, or 22 for high density rather than 18 as with an IBM clone. The Amiga standard HD floppy had 1.76MB of space (880kb * 2).
Yep, and because it was "all software" you could then use something like DiskSpare to push that into 960/1920 using the same "non standard tracks'n'gaps" tricks.
I am also an Amiga owner, and I think the Amiga has the most flexible floppy disk system of all computers. Besides regular Amiga formats, it can also handle PC and Macintosh formats as standard, and can even be further customised if there's a need for it.
I remember to hassle of copying Amiga Disk Format (ADF) images to PC. ADF was 880kb and the Amiage couldn't read 1.44Mb disks, so I had to format them to 720Kb size and compress the 880kb fil to fit. That is how I manage to get all my saved games (and hi-scores) from certain games ported to PC and I still have them.
I remember having a game for my Amiga called … Starglider II ? .. on that one single disk was both the Amiga game and Atari ST game. My thought back then was that since both systems were 68000 cpu based, as long as both could read the boot sector (so would have to be MFM to please the ST that used essentially the PC 720KB format.. let’s not split hairs about how early TOS tweaked it) then the boot code could figure out what system it was on. And with the ST single sided 360KB disks were the common denominator and all Amigas having double sided since day one, then the ST could load from just the common side and the Amiga load the 2nd side. Anyone know anything more definitive? Was that a good conjecture on my part as a teenager back then?
You can also squeeze a bit of extra space by reducing the copies of the FAT from 2 to 1, which is fine if you don't plan on getting one of the copies corrupted. This halves the number of sectors lost to the FAT. To help with speed, you can add the 'buffers' setting to the config.sys, increasing the number of sector buffers and allowing read-ahead buffers as well, which may mean the interleaved sectors can be put in the read-ahead buffer, allowing a track to be read in fewer rotations, eg buffershigh=64,8 Also, see the 'smartdrv' command for speeding up floppy disk access. I don't remember if it was available from the w95 floppies or if I kept a copy from 6.22, but I would make sure I added it (with the 'A' parameter to enable caching + readahead etc for the floppy). Man, such obsolete knowledge knocking around here haha I wonder if I can low-level format my brain to get this back? Btw, the MS .cab file format used the Diamond compression/format which seemed so slow, I always figured the naming was because "Diamond's are forever"
Interesting! Thanks for sharing. There is so much more about diskettes I don't even know. I am completely blown away how many people are watching this video - so much for "obsolete knowledge".
I do this from time to time when I'm trying to write a disk that has just a couple KB more than will fit in a standard formatted disk. I don't usually drop the 2nd FAT (although I'm not entirely sure why I don't...), but I will reduce the root directory size to, e.g., 64 entries (which is usually more than enough), or change the cluster size from 512 to 1024, or even higher, if I'm trying to copy a driver installer that uses large compressed files. That, in effect, decreases the size of the FAT, giving you more room for data. I haven't yet run into any trouble with any version of DOS or Windows that were offended by a disk that diverged from the way Microsoft's format tools do it (well... caveats...) The document floating around about the FAT format, from Microsoft, expressly requires compatible implementations to read the BIOS Parameter Block and do all of the calculations, vs. making any assumptions. The caveats: Just for my own curiosity, I wrote some tools to read and write DOS partition tables and FAT volumes. I've used these from a Linux CLI to prepare hard disks, or images, for use in retro PCs. Windows (9x) will fail to install if you don't comply with _some_ expectations, like the OEM string for example. In some cases, depending on what you changed, it might pass the Scandisk check, but then the installer will fail. They're perfectly valid FAT volumes, but there are some trivial things up with which the Windows installer will not put.
@@bitsundbolts this was common knowledge for a programmer in the 80s and early 90s. this level of information was widely discussed in popular computer magazines like PC Magazine. References like Ralph Brown's interrupt list were freely available.
Interleave and sliding are all about having the right sector under the head at the right time. If you don’t have the right sector under the head when the drive is ready to read/write, the disk has to make another rotation, slowing data transfer.
Yep, interleave 2 means that to get to the next sector on a drive you rotate the disc 2 sector sizes, so the physical layout with interleave 2 and 21 sectors is: 0 11 1 12 2 13 3 14 4 15 5 16 6 17 7 18 8 19 9 20 10 This gives the installers one sector of time to process each sector . Another trick from the old days now used on hard drives is to use larger sectors by reconfiguring the FDC in the computer without changing the standard TEAC compatible floppy drive that doesn't know about bytes and sectors, it just transfers the bit stream to and from the head . Having installed Win95 from floppies before getting a CD-ROM copy, I can tell you that the floppy version contains only the stuff in the numbered CAB files in the main install directory, one CAB per floppy, none of the bonus software in other CD folders . I'm actually surprised the DMF discs contained a file system instead of straight CAB files, but I guess that was needed for MS Office floppies under Win 3.x . The 1024 cluster size was used on 320K and 360K floppies, so was already in the common floppy drivers etc. 320K floppies were the same as 360K, but 8 sectors/track allowed the entire DOS 1.0 FAT to be a single sector .
There were official tools distributed by MS at their old BBS, FTP and some MSDN disks. The name of the tool and ZIP file is called DIAMOND. The DIAMOND tool not only is used to create CAB tailored software installers, but also the DMF disks. CAB fileformat and Diamond DMF floppy format are meant to work in tandem. As you said, DMF isn't meant to be used in DOS, so Floppy 1 (Boot/MemManager and Boot Tools), and Floppy 2 (Setup and Precopy CAB) are standard 1.44 disks. Once Win31 Standard mode is launched from decompressed Precopy CABs and "graphical setup" launches, LZExpand.dll and its VxD will layer on floppy disk access, and Setup will be able to copy and expand from DMF floppy CABs safely. This is also why NT4 doesn't read/write from DMF Floppies. IBM used similar strategy to distribute Floppy software in a fewer floppies. It is called XDF format. But unlike MS, IBM included the required tools built in OS, and while in OS/2, OS floppy driver can read the format natively. I guess PCDOS can also read XDF (no boot), as PCDOS floppy 2 and onwards were XDF if I remember well.
I had no idea you could do this. I have fond memories of the floppy years, thanks for this, I would love to see a video comparing both Windows 95 versions.
The Linux "fdutils" package included a program called "superformat" which allowed formatting standard floppy disks at up to 1.992MB (I believe using mixed sector sizes). The downside of larger sectors is that if a sector goes bad, you lose more data.
Nice video! This took me back. I was 20 when Win95 came out but before that ran a BBS using DOS on a 286. I remember so many nights sitting inserting floppies. 🙂
Fascinating video, and never realized the official Win95 floppies were different in size. The one copy of Win95 I had on floppies was created via a utility on a Pac-Bell system. Now I wonder if the utility did this in the background for the other disks besides the first couple.
When I was working at the computer store back when I was in high school, one of the technicians was pretty crazy. He was obsessed with getting the smallest possible Windows 95 installation that will boot into the GUI. He managed to get it down to less than a single standard floppy disk, and it still booted into the GUI. Absolutely insane.
Most of it is "support for something". If you strip out "something" then you can strip out "support for something". If you have "in built" file system compression it let's you go even crazier. The old QNX Demo Floppy is probably the hallmark of it, but they were "sort of cheating" because QNX was designed to be modular from the go so stripping it wasn't all that hard.
@@ithecastic Obsessed, yeah that probably wouldn't have been too bad. Lack of social skills, sure lots of people have their personality quirks. But then he'd occasionally say something that was obviously meant to be "funny", and perhaps I (a 15 year old kid at the time) won't take him up on his offer to hang out at his place on the weekend.
I saw this video 25 years late.. I have copied MANUALLY all the files I could fit from each image after disk2 to a standard formated 1.44MB disk thousand of times because I didn't know how to fit all of them at a single disk, hence it usually took me hours of work and copying-pasting files from the image to the disk and vice versa.. Veryinteresting video, all my life I thought these were "special disks". It brought me a lot of memories of the past. Thanks!
This is really cool! Thanks for the explanation. I always wondered how they'd done this. From what I understand - a lot of the sounds were cut, as were the background images and mouse cursors. Also there was usually a folder on the CD with extras in, such as videos and games which might explain where the extra space was used up.
Great stuff, I rarely subscribe to the channel after watching one video so you can be proud of yourself. Answering the question at the end of the video, I would love to see a sequel.
The additional tracks are closer to the hub in the center of the disk. It's risky to store information there, both because there's less area in which to store data (the disk rotates at the same angular speed, but the heads travel less linear distance in that angle, so the data is packed together tighter and may not be stable) and because some drives' heads physically cannot move there.
As another user commented the versions are the same between the CD and Floppies. What you do not get in the floppy version is any of the extras. Both versions however have the same number of cab files which is what is used to install windows. Cab files are just compressed files much like zip files.
I remember to hassle of copying Amiga Disk Format (ADF) images to PC. ADF was 880kb and the Amiage couldn't read 1.44Mb disks, so I had to format them to 720Kb size and compress the 880kb fil to fit. That is how I manage to get all my saved games (and hi-scores) from certain games ported to PC and I still have them.
I was in the Windows 95 beta group. I was unable to successfully install Windows. Some received the CD. They sent me the floppy disks. Spent nights with a Microsoft engineer often working until 3AM in the morning. They finally asked if I would agree to ship my PC to them. The problem turned out to be an old floppy controller. They would not confirm but I believe the problem was reported in the wall street journal. I know they were scared. Fortunately my issue was rare and their was not a flood of failed installs.
Ahh, the good old days of trying to squeeze every little bit out of the media that we could. At some point in time ~25years ago or more I was formatting a lot of my "data" disks this way using tools like 2M that were closer to magic than to code, not only messing with floppy/drive parameters in the "official" way, but also injecting code to the bios and such. It was nice seeing 2M even mentioned remotely here (on the related articles, wikipedia page). Some of those disks still exist, and now I have to wonder if after all this years and (ab)using those unsupported cylinders at the end, they can still be read properly or not. Gotta try someday. Great video, wish I could show it to my younger self to answer the oh-so many questions on this topic.
@@sveinungsandsbakk416 I have some floppies from around 95, all the regular 1.44 disks are still readable, but none of my 2m disks are readable today, which is sad.
@@gacsizclickon Yeah, the tolerances are tighter for those exotic formats -- which is specifically why they weren't the norm. The actual disk isn't structured any which way, it's just the controller and, to an extent, the drive's physical and electrical capabilities that really define how many bits you can squeeze in there. The compromise is how compatible and resilient you want it to be. :-)
30 floppys for the version i got. My Father got me a 486 cnc work computer and it had only a diskette drive, then my school got Windows 95 on disc and way of copying it on diskettes. Took those home and installed Windows 95 on my machine, what a great windows. Thanks for sharing, i didnt know the original diskettes had 1.68 mb of data.
Different drives had different sounds so what you loved would depend on the machine/drive. I always loved the sounds of the older ones that were, well, noiser. It was almost as good as the sound of good ol' dial-up.
I was really happy when I discovered "FDFORMAT" which was a set of two programs (the other being called "FDREAD" and was a Terminate And Stay Resident or TSR program). It allowed you to reformat floppy discs to use 82 tracks instead of 80, use some of the gap space for extra sectors per track and to reduce the number of root directory entries which would leave the sectors normally used for the root directory free for data storage. The funny thing was that some formats, such as reducing the number of root directory entries, were compatible with Windows without any other programs needed. Only the more "exotic" formats required FDREAD to be installed in order to allow Windows to read the disc successfully. If you wanted to get a large file onto a floppy disc which was just a little too small for the file, reducing the number of directory entries might solve your problem. In some ways, it's a little disappointing that we now have so much storage space available that we no longer need ingenious innovations like FDFORMAT to squeeze that "little extra" out of our hardware.
@@forbiddenera this is actually underused quite a bit. People always assume that old CPUs would be struggling with decompression too much. I was really surprised when I tried a compressed executable on an Atari portfolio, running a 4.7 MHz 8088. The program loaded noticably faster when compressed
2M and 2MGUI were also fun to use with compatible drives and disks. This rapidly improved my understanding of error-correction techniques too, which made it even more fun to max out the sizes 😅 edit: Also, OS/2 had XDF and XDFCOPY for making almost 2MB disks, but was built into and part of the OS/2 Warp installation from floppy’s.
Oh yes. Being a big fan of OS/2 Warp back then, I've made the XDF my "format of choice" (even though using it for everyday storage wasn't straightforward); years later, when it came to copying / backing up my old files from these floppies, I regretted it profoundly 🤣
@@LoftBits And so it was with every non-ubiquitous format. haha I've learned that lesson more times than I would care to admit. There was quite a while there where I would yell at my former self, saying "I don't have anything to read UC2 archives anymore! Was it REALLY imperative to save the extra 1KB over a ZIP file??" And then I did it again, with a lossless WAV compression utility called Charlie Packer. There was exactly one program that could read those files: Charlie Packer. I think I *still* have c13 files on my NAS somewhere...
I think the interleave parameter is for a physical phenomenon: the floppy spins and as the system processes the data from the sector currently being read the disk spins unter the head. So to get a continuous stream of data it would be good to not wait about a full rotation until the next sector comes along again but store the next sector a bit later on the disk. So imagine 4 sectors on a disk, you don't store 1, 2, 3, 4 but more like 1, 3, 2, 4, this way you have a one interleave. I think it works that way and I hope that explanation makes sense.
That is exactly why it's done. However, an interleave value of 1 actually means that there is no gap at all. The number basically tells you how many disk rotations are needed to read or write one full track.
It was mostly a benefit for older PCs that might take enough time between finalizing reading 1 sector and preparing to read in the next. An interleave gives it more time between that. If not given that time, it would need to wait a full rotation to read each consecutive sector, or if its timing is especially strict, may even time out or something before it reaches a full rotation.
Very interesting. I was using VGA-Copy for this purpose, but I never knew how it worked :) BTW Not all floppy disks could handle 1.7 MB format, I had to test every one and mark those that didn't. Thanks for explaining this little old mystery :)
Increasing the track number is pretty much the same as when you overburn a CD-R, it will record further into the external margin of the disk, which in the 3.5" floppies can actually cause mechanical issues with some older drives and on those if you keep doing it you will kill the drives mechanically, one of the rare occasions back in the day where software could actually cause physical damage to hardware. Prior to overclocking that was next to impossible.
You can't damage a drive by using it, except long-term wear to end of life. It was just increasing the density. 1,44MB was set to the industrial standard. It was considered the most efficient quality demand at fabrication of disks. Anything beyond it was approveably unreliable.
@@manuell3505 If you tell the drive to seek to e.g. track 90, it can't really do that. Either there is a safeguard preventing stepping beyond a certain point, or you simply crash the head onto a mechanical barrier. The second option will at least result in a misalignment of the head, which in turn will make your drive useless. That's not only tear and wear.
As I recall, the 13 floppy disk version of Windows was lacking a number of optional components, such as additional sound schemes and system tools (the Windows 95 CD--early OEM release--I have at hand has a utility to create a custom install script). Note that the initial release of Windows 95 I have only supports 8.3 file names and shipped with an FDISK executable that only supported FAT16, a later OEM CD I received from Microsoft after market-release has a version of FDISK that supported FAT32.
The german disk version of Win95 that my roommate bought at the time consisted, of 78 floppy disks. He bought it because it was ten Deutschmarks cheaper. We laughed at him for weeks...
Amiga could write 1.79.MB on the same floppy standard, so 1.68 MB weren't a problem. The filesystem you use decides how much you can store on a floppy. The floppy itself can store up to 1.9.MB or something and it doesn't matter if it's done on PC or Amiga.
We did install Windows 3.1, Windows 3.11, and Windows 95 using floppy disks when they first came out. People had HDD yes, but only a few had CD ROM drives. So there was always someone on the college campus who happened to have a plastic bag full of such floppy disks and went around spreading the love among us :D
The theory of copy protection was already absurd at the time because you could also get Windows 95 on 5.25" 1.2MB floppy disks and copy their contents on 3.5" 1.44BM disks with standard format, instead of 13 disks you were going to need 21 but if you weren't going to pay for Windows 95 you had a lot of money left over to buy floppy disks.
Ah yes the good old DOS formatting days. Back in the day i randomly found the 2M formatting tool & discovered that the quality Teac floppy drive i had could format quality floppies to the largest 2 million bytes (aka 1,97kib i think) extended format. of cause you needed the 2M driver software to access those larger formats as it wasnt natively supported. Most of the backups i did was with the slightly smaller 1,8 or 1,9 sized formats to be on the sure side. Sadly the quality of floppies dropped with time & it was really sad in the end where you could buy a 10 boxes of of 10 floppies each & you had to trash half of them because every other failed to even format to normal dos format immediately. Of cause the price had also drop to a point where they was nearly giving them away for free. Good happy times thou :)
I remember as a kid, I was able to format 5.25" HD floopy disks to 1.6MB instead of 1.2. We used Dos Navigator, and it had this option. As I remember, it worked only with some disks which were in really good shape, and it was not too reliable.
Yeah it depends on the quality of your disks. And probably the drive as well. I got the 5.25 ones mostly to 1.4MB. Bit of trial and error, then dump data on it and verify that it can be read correctly before usage.
I've made the install floppies for Windows 95 manually using Linux and pulling the cabs off a Win95 CD. It was an learning experience about how floppy drives work. A lot of stuff on the Win95 CD is extra stuff too. They had music, themes, music videos, and Hover on the CD I had.
Ah, memories I remember setting in my chair with my chips, Mountain Dew, and watching TV installing one disks after another clicking the continue button (its been a long time). The 1st time I was excited, the 15th time mad with my head on the table wishing this was faster. Thanks for the memory's
A video about floppy disks in 2023 with 58,000 views and 346 comments. Amazing. Geek score 10/10. The only thing missing in this video is an explanation about how increasing the number of tracks / sectors per track actually physically results in a different layout on the disk compared to the conventional 1.44 MB layout -- that space has to come from somewhere and not every viewer is going to have an intuitive knowledge of the layout of cylinders/tracks/sectors.
I worked at a computer store when 95 came out. Almost every computer had a CD drive at that point. Few had CD/RW drives, which may be the confusion in the video. I can only remember installing 95 using floppies a couple times of all the computers we built / sold. Now, 3.1, that was usually on floppies, and it was a pain in the butt.
A large portion of pre-existing PCs that supported Windows 95 did not have a CD drive, and that is what the floppy disk distribution would best serve. Also I think perhaps you're thinking of Windows 98? Most new consumer PCs would have a CD-ROM drive at least as an affordable option late 1995. However CD recorders were still very expensive at this point (>$1000) and not typical and CD-RW would not exist for several years.
@@oogieboogie232 - You are correct that CD-RW drives were very expensive at that time. I think we were getting them for about $500 each. I don't know what we were selling them for, since I was doing PC builds at that time and not on the retail side of the business. We sold very few systems with CD-RW drives in them. But, we put CD-ROMs on almost every PC we put out at that time. We bought in bulk and paid wholesale, so I think we were getting them for around $100 each for the drive and the controller board (again, not sure what we were charging retail). We were primarily in the business of building new computers and doing hardware upgrades, so we very rarely did OS upgrades, and when we did it was usually for business customers, so they were using NT and not 95. I was only doing that from early 95 to late 96, so I know I didn't deal with installing 98 while there. After that, I went to work for Honeywell, and only delt with NT & 2000 there, and didn't deal with any consumer versions of Microsoft products.
@@henson2k - Yes, it was done, just not as prevalent as this video would imply. Pretty much exclusively only on systems that didn't have an internal or external CD-ROM drive, and almost always for home users to upgrade their OS on already purchased systems. When we built systems that didn't include a CD-ROM drive, if we had a CD-ROM drive laying around we'd hook it up to do the install, then take it back out of the system.
A lot of PCs back then had CD drives but not all support booting from CD, even up in to the XP era it was common to initially start the install from floppy to get the drivers in place for the CD-ROM.
It was a very small window of time when higher capacity floppy formats were a thing. 100M Iomega ZIP disks kinda replaced it for a short time, until the Click-Of-Death made them unreliable, but by then, CD-RWs and flash drives had replaced them.
@@deltaxcd I think there may have been some compatibility issues with the format. I don't think all floppy drives and/or floppy controllers could support it. I had a client at the time who wanted to upgrade a brand new computer to Win95 with floppies, and it didn't work. The floppies read fine on another computer, but not on that one. I wound up copying all the floppies to the hard drive on another computer, backing up the install files onto 15 or more blank floppies with PKZIP using disk spanning, restoring the files to the new computer's hard drive, and installing Win95 from the hard drive. This same computer was not able to use the built-in backup routines in Simply Accounting, a very popular accounting package, to back up to a floppy disk. The backup would always fail. I discovered that disabling the floppy disk driver in Win95 would revert to reading and writing through MS-DOS, which would allow the backup to work... until the driver would randomly re-enable itself. In the end, I had to set Simply Accounting to back up to the hard drive, and I put a batch file on the Win95 desktop to copy the backup to a floppy disk. This did not please the client at all, as it was an extra step, and they felt I should be able to get the program to work as intended. I lost a bit of my "miracle worker" reputation due to that stupid floppy drive. I always thought it was a bit ironic that floppy drive and controller compatibility started to become an issue at the end of the floppy drive's lifespan. Usually compatibility issues arrive at the start of new technology, and work themselves out.
Fascinating. I'm also curious about what was cut for the floppy disk install of Windows 95. Maybe it was drivers? Or that promo movie I remember being there where the showed the old Windows 3.x desktop fading away into the clouds?
I think I know what you mean. This video was in the OOBE folder on the CD-ROM if I'm not mistaken. I wondered about the abbreviation of the folder name that time - and there was no internet yet to look it up. Later, I found out that it means "out of box experience".
Anything that wasn't in the win95 directory wasn't included. In addition, some of the accessories were also missing, Microsoft used to have a download on their FTP server which added the missing components back to a floppy install.
I used to use a disk doubler back in the day, allowed me to format a 1.44Mb floppy as a 2.88Mb floppy. The resultant floppy didn't work in every computer, but those it did, boy was it a lifesaver :)
1.76MB was standard size for Commodore Amiga HD floppy drives. I have original win95 and office install floppy disks. I set up win95 under emulation on my Amiga. It worked but was really slow, even with a 68060 accelerator card.
Thanks for the video! WfW 3.11 was my last floppy-based installation. Fast forward 25 years, bite/cluster/sector geometries have morphed into an unexplainable mechanistic methodology when you write a file on an enterprise SSD. While sometime confusing, it is possible to figure out the geometries of writing/reading floppy disks and hard drive, but I just had a bad time when I wanted to discern the inner working of a multi-chip flash drive controller, where multiple optimisation and reliability algorithms crosses together...
CABS are also highly zipped. Pushing this floppies this way, give more reliabilty issue, thus data errors, These floppies were natorious for errors and failure when using them. CD version has the Windows extra tools and the bloatware videos.
Great video! Fun to watch. I've used FDFORMAT but I never really understood much about it. At the time, I was trying to get 1.8mb floppies working, which I think also required a TSR? I can't remember.
I remember that I used 2MF to format 1.44MB disks to have 1.88MB on them (1,931,264 bytes). It required 2M, a small TSR driver to work because it somehow fooled also the floppy controller to make it work in a really unusual way. It was not just surprisingly stable but also really fast as it optimized the arrangement of the sectors. And the bonus part: every formatted disk contained the driver hidden in its boot sector so it wasn't even a problem if you forgot to carry 2M on a regularly formatted disk to your friend. It was enough to boot on the disk and the driver loaded itself automatically. I discovered it accidentally when once I forgot removing a disk from the drive.
Interleave generally give the milliseconds in delay that the controller needs to react to writing data. It depends on the IDE bus and bus system and what is more appropriate. HD density disks have 2MB and can be formatted with 1,6MB DMF format. The cuts were just tools that were related to Ressource Kit and other add-ons such as Hover etc.
Interleave: after reading Sector 18 on track 1 the disk spins while the head moves to track 2. To read sector 1 on track 2 the disk needs to turn until sector 1 arrives again, which is 95% of the rotation. By placing sector 1 on track 2 next to sector 2 on track 1 you can omit that wastefull time of rotating 350 degrees. Depending on the speed of the read/write head the optimal interleave can be 1, 2, 3 or 4. The time rotating the interleaved sectors must be slightly larger than the time it takes for the head to position on the next track.
My Aunt brought a copy of this home from work, It was either Thanksgiving or Christmas, I sat at her desk, didn't even turn on the PC: I opened the box & saw the amount of Floppies! "THIS MUST BE EPIC!"
Thank you. I remember pondering this "WTF?" The BIOS screen sure brings back memories :) I am glad I learned all the DOS commands as a kid as there are still some uses like BIOS and hardware firmware Loved that "Marketing Formula" back in the day too change base 16 to base 10. "Thanks guys..."
I think that on CD version there was an intro movie copied and displayed upon first user logon right after installation. There was a C:\Windows\Media (or something simmilar) directory with this movie and it was the first place to look for lost disk space.
I vaguely remember Microsoft's installer failing to continue when ran from copied diskettes, despite them being cloned from the originals for backup purposes. Analyzing the first few sectors, I noticed an identifier of sorts that was different on the originals vs the copies. (It was "MSDMF" or something...). After manually changing it on the copies, the install was successful. EDIT: It was the FAT ID that was different. Windows 95 OSR2 was checking for "MSWIN4.1".
I remember using 1.68 MB formatted diskettes around year 2000. Of course CD ROMs were abundant but this before I had a CD-RW drive or USB flash storage was around, as well as fast Internet, so data transfer was possible mainly with floppies. I routinely used multi-part RAR archives, and every extra 200K went a long way.
@@LagrangePoint0 Astana is a nice place to visit but not a very nice place to live: extremely cold and windy winters, very hot and dusty summers. I live in Almaty now, summers also hot but overall much more hospitable. I’ve been to Chile and Perú on business trips, unfortunately no other South American countries.
@@veschyoleg Well, if you ever come to south america again, avoid venezuela AT ALL COST. Btw, what do you do for a living?, what kind of jobs are available over there at Almaty?
I remember messing around with floppy disk formats 30 years ago on my Atari ST. I found that I could format the disks with 82 tracks 10 sectors, that's half of what your HD format, but those disks couldn't be read on an IBM. I also made my own personalized boot sectors. As for interleave, on SD diskette, an interleave of 2 was faster than interleave of 1. It's down to how fast the disk spins compared to how fast data is transferred from disk to computer. This is also why an interleave of 2 is slower than 1 on HD diskettes.
I have the windows 95 floppy disk set, I think mine is 27 disks for the extra features. Interesting to install. You boot on the first disk, but you get an installation GUI after only the second disk!
When my 20 MB HDD died along with the controller (released A LOT of magic smoke :) ) I looked around for "bigger floppies. I used HD-COPY by Oliver Fromme that played around with tracks and sectors without TSR, for me it made the most "stable" for normal read/write use disks back in the day, quite larger, and it would also "revive" "track 0 bad" disks at least temporarily. Then with TSR I used 2M a lot, the standard 2M format ones were quite reliable, the "guinness" ones were more finnicky.. Fun times! I could play Leisure Suit Larry (I think 3?) installed on those larger floppies, as it needed slightly more than 1.44 space to install :)
I remember DOS Navigator has also an option to format floppy at 1.68 MB. And I used to format my FDs with that tool to got some space more, that was useful with playing around with WinRAR, that can make its archives with automatic volume size, detecting it when accessing to a volume. But when I installed i guess Windows 2000 of ME (can't remember now), i found out the 1.68 floppies cannot be read under that system. It appears just like unformatted disks.
Interleave is sector ordering: With interleave 2 a track with lets say 4 sectors is written in order 1,3,2,4. So the computer reads sector 1 and has time to process the data as long as sector 3 is under the head, then it reads sector 2 and uses the time sector 4 is under the head to process the data, it continues to do that with sector 3 and 4. So it needs 2 revolutions to read one track. If you use DMA and don't use buffering then you don't need time to shovel data around. Then you can read directly to the desired address in memory using interleave 1 which is two times faster.
8:34 looking at the See Also section and seeing the [2M] fills me with nostalgic feeling, I use that a lot before I finally upgrade to FAT32 capable windows.
I would assume MS used some sort of compression in those CAB files on the floppy disk version compared to the CD which may have not had any compression. Otherwise, the CD version may have been for newer computers, so the extra space would've been drivers, and the floppy version would be for older hardware where the drivers were more limited. Windows 95 CD also had that Windows 95 Plus crap which had extra themes.
Yes, the CAB files are actually custom compressed archives (either ZIP or LHARC format, I can't remember). I used to repack them to fit custom sizes back in the day. It all escapes my memory now though lol
It’s actually enjoyable formatting with floppy disk back in the days. Back then system gets really slow after a while. Reformatting with floppy disk gave a super excitement about getting the pc in decent speed again. Then… Warcraft, Diablo, descent, StarCraft, and alot other games are all standing to be install next xD
Regarding the question at the end, I think the CD version is so much bigger because of all the included drivers. The floppy version just installs the operating system, while the CD version can help configure your system (key word "can").
A reduced driver library crossed my mind as well. They did have some music videos, game demos, and some Microsoft Marketing material on the CD-ROM, but I do believe, like you, that there have been more cuts here and there.
I had a retail version of 95 on floppies and it was some months before I got a PC with proper drivers for it. I remember going from using it with 16 colours to the full range and the startling effect of seeing pictures and websites as they were meant to look.
NEC made a 1.44M floppy drive with a linear actuator to move the heads. It was super quiet, only made the tiniest of *eeep* sound when accessing a disk. I should have kept the one I had because I've never seen another one.
I had a tool for creating DMF disks. It included a patch that was placed in the MBR to act as a disk reader controller. In addition to everything shown in the video, I managed to have a Windows 3.1 installed on a DMF disk, which was later compressed using drvspace or doublespace, creating space for a trimmed but functional Windows 3.1
"Win3.1 on a floppy", the ancestor to the now more familiar "Windows/linux on a flash drive". Wouldn't surprise me if within the next few versions of Windows, Microsoft combines the fact that it can detect when something's a USB flash drive, with the want to prevent copying of the OS without payment, into the inability to install Windows to any type of removable media.
I remember multiple configurations and utilities in the times of MSDOS. One very famous was FDFORMAT. The resident allow it to use formats that should be allowed (but not) by MSDOS, 512 sectors based, and increasing tracks. Almost all floppy drives of the time allowed more sectors per track and up to 82 tracks at least, although most units supported even more tracks (some 84). Other was 2M, that besides provide an alternative to FDFORMAT format support, that allowed a mix of different sectors sizes, while the resident faked MSDOS make it thinking that it was just multiple 512 bytes sectors. That configuration allowed even more equivalent (now virtual) sectors per track. I modified this utility to myself (I met "Ciriaco", the author, personally, in the university), supporting an even bigger sector with a configuration that support even a bit more. All these formats where supported in Linux through the "superformat" utility. And, just as last, the "2mGUI" utility. It used a one unique sector that it was TOO BIG, and used the trick of reset the controller to force the floppy to don't override itself. That was the utility that was able to write a floppy to the maximum capacity. But the problem is that write required a precise timing and talk directly to the floppy controller what was almost unable to be adapted to windows and linux, so that format was used exclusively in MSDOS with the same utility. As a curiosity, using superstore (real-time compression-decompression of a virtual filesystem that emulated a FAT) + 2M, was able to create a one floppy version of Monkey Island. Computer tell tale of an old man on the times where Internet where a (mostly) lab thing and floppies reign supreme between people X-D Now you can play in a browser that run a virtual machine over another virtual machine to run a "DOS" and download all of this from "Internet Archive" with a search and a click.
You should have seen the size of the Software Developer Kit (SDK). It came in a box bigger than a microwave oven and the manuals filled a whole bookshelf.
In the good old times I did a mod to multi-i/o card that includes 27 MHz oscillator and a 74xx chip, I don't remember what one, allowing to switch between 27 MHz and the original 24 MHz. The input of the contraption was connected to one bit of LPT2 on the same I/O card. Another LPT2 bit was connected to the 5.25" drive itself, allowing to change its rpm from 360 to 300. The contraption was invented by one of my friends, a computer geek, who did several other crazy things including cooling the overclocked 486 with a glass jar filled with water, placed, lid down, on the CPU. This mod allowed to (1) format 18 sectors on a 5.25" HD floppy, so it can replace much more expensive 3.5" (2) format 15 sectors on a standard density 5.25" floppy so they can replace 5.25" HD, (3) using a custom written formatter, format both 5.25" and 3.5" HD floppies to about 2.1 MB. The main motivation to do the mod was about 500 5.25 SD floppies I had on the desk that became usable again.
Once I used a tool which formatted different sector sizes on the tracks. IIRC 5x2KB, 1x1KB and 1x512Bytes on a track, of course special driver software required to operate such floppies, having virtual 23 sectors per track. This converted the gaps between sectors into usable space. With 82 tracks this resulted in nearly 1.9MB of space on the floppy. I still wonder if there was an option to reduce the numbers of FAT to 1.
I remember messing about with (IIRC) LLFormat to create diskettes that could hold 1.92MB of data, but they had no FS on them. I used them with a friend of mine to transfer large games by putting the game into an ARJ, then tarballing the ARJ into slices and writing the raw tarball to the 1.92MB diskette. Then reading the raw data back from the diskette in order to open the tarball and unpack the ARJ. Upside of this was that it needed less diskettes, downside was that you needed to be able to store the data at least twice on your HDD, as you'd need to unpack it twice. In the end we managed to source a second QIC-80 drive, which was much more convenient. Sure it was slow AF, but it'd hold 40MB on the short tapes or 80MB on the long ones, double that because we had identical drives and could use hardware compression. It was kind of awesome having teachers in school be all confused about what these QIC tapes were, but also less awesome that both of us got sent to the principals office because some teacher thought we had stolen a tape from school. Thankfully the IT guy in our school was awesome and would be more curious about what we did with said tapes than where they came from. Also the school used DLT for its backups, so their tapes weren't compatible in the slightest with our QIC tapes. Ooh the benefits of having a father who worked at DEC. Also, yes I still have those tapes, yes one of the drives does still work and last time I checked the tapes were all still readable. But then again that last time I checked was to gather the data from tape and store it on less-than-reliable CD-R discs, most of which have since died to rot.
"Using the marketing formula" 1MB was originally 1024^2 bytes. MiB is a later invented term for 1024^2 so that marketing could use 1000^2 for MB to shrinkflate their drives. This even resulted in successful lawsuits for deceptive advertising, but in the end industry permanently changed the language.
IIRC the Amiga high density drive for the A4000 spun the floppy at 1/2 speed, to keep the data rate the same as before, because the floppy controller and audio chip (Paula) was never upgraded from the original A1000.
There was a difference in readability of standard 1.44 floppies formatted with different settings. They would often not be readable past about 75%. I think that, when invoked from Windows, the timining of the format wasn't stable. Sounds from the drive came at slightly irregular intervals. DOS Navigator had options called "forced" with "optimize" that made a previously defective disk work again, even when later written from Windows. I think optimize might have involved sector shift.
Interleave is all about read speed.
You see, most of the time, the computer will read more than one sector. But when reading a sector, there is some overhead. Because the driver has to hand off data to the OS, advance its buffer pointers, decrement counters, stuff like that. So what happens is, the computer needs a little extra time in between each sector. This could be accomplished by just leaving larger gaps, but that would waste space.
So, what you really do is, you change the order of the sectors on the track. Instead of storing 9 sectors as (1,2,3,4,5,6,7,8,9) and interleave of 2 will skip every other sector, arranging them like (1,6,2,7,3,8,4,9,5). That means, after reading sector one, the computer has time while sector 6 is moving past the drive head, and then it can read sector 2. Then again it can do "housekeeping" while sector 7 passes the drive head, and go on to read sector 3.
Without interleave, a slow computer would have to wait a full rotation of the floppy until it could read the next sector, wasting a lot of time.
The same technique was used on early harddisks. Since they were faster than floppies, the problem was even more impactful. And you could get better performance out of your disk if you determined the optimal interleave for your specific system. Because it depends on the speed of your system, the rotation of the disk and the controller, the optimal interleave has to be determined for each specific system. And it could be fine tuned to not miss a sector on sequential read, but not interleaving to much.
Hope this helps.
That logic went all into the controller of the harddisk.
Thank you for excelent explaination.
Man - you really take me back.
Thank you! I have always wondered what Interleave means.
Guess I should have read the comments before replying with a short but similar answer. Interleave way back when was a major issue with MFM and RLL hard drives. Too small and the drive would be crazy slow, too large and it would just not be as fast as possible. I recall using Gibson research Spinrite to calculate and adjust the interleave on old drives.
Interleave has to be increased to 2 for a 21 sector DMF, as there is just not enough space / time for the sector gaps, the drive just cannot synchronize the read... a bit like for very old HDD where the interleave was about 6 for a slow 8 bit controller, and down to 2 for an unbufferred 16 bit.
The slip / skew options are powerful when used right.
On an 18 or 20 sector, typically a skew factor of 3 on track, and 0 or 1 on head gives an improvement, as otherwise the drive will miss the next sector and waste a rotation on track stepping, while some drives may be able to switch the head fast enough.
The sector alignment of DMF may already provide a skew factor.
Also, one beware on T82 (more so if you risk T83 or T84). If the drive uses a lead screw mechanism, over-tracking can jam it... bumping the end stop on other mechanisms is not great for them, but not usually fatal.
Secondly, if searching for the over tracking limit, or just using T82, use verify after format rather than the verify at the same time (which may be faster), otherwise it won't know that its overwriting the track while its endstopped
What is this floppy disk interleave thing anyways? I've literally reverse engineered the floppy disk formats in hex disk editors and never heard of any interleave factor.
I've even made my own versions of Win311 that fit on a single floppy disk. Tried all formats including these, and get a very regular timed tick tick tick readback.
Thought that interleave only applied to super early hard drives.
Edit: I forget, I made sure my files loaded in order and had no fragmentation.
Interleave make the floppy slower for better performance on slower machines. It does not write the sectors sequentially, so e.g. 1, 9, 2, 10, 3, 11... for interleave=2 This halves the transfer rate because the drive has to rotate two times to read a track. So it is ideal to have a interleave that make the drive just a tiny bit slower than the max transfer rate of the machine. Otherwise the drive has to re-read sectors all the time totally tanking performance.
@@southernflatland Interleave affects the way you read a track sequentially. The floppy controller on some machines cannot read all sectors on a track in one rotation if they are in sequence /ie back-to-back), but read one sector, wait one rotation and read the next... on a standard floppy that means 18 rotations to read all sectors in sequence on a track. With interleave you mix them up, so you can read it faster, Basically interleave of 2 means it takes 2 rotations to read all the sectors of one track in sequence, with interleave of 3 it takes 3 rotations and so on.
@@southernflatlandinterleave will only be usful for older, slow machines/io/drives that cannot transfer the data per sector quick enough and so miss the start of the next sector.
Skew is the same, slow, old, etc. This where you change tracks (move heads) and you miss the start of first sector of the next track.
@@recycledsteel3693 Oh I get you, I do. I'm familiar with the interleave/skew thing, just never heard of that for floppy disks.
Makes me wonder what byte I missed in the hex decode of floppy disk FAT12 format.
So you got the Windows 95 install on floppy disks. I see you have chosen the path of pain. OSR 2.1 HAD 26 floppy disks.
OS/2 had roughly 100 back in the day. You could make them from the CD per batch file. Problem there was that this only worked until you hit a bad floppy and then you had to start the process all over again. Path of pain indeed.
So be it 😅
I actually had to do this once. Installing Win 95 via Floppy 😅
Oh yeah, good times... Good times...
u mean the path of fun ? :D
The CD contained a folder called PRODUCTS with 296MB in size. It contained advertisements and demos for dozens of Microsoft products.
man that took me back, thanks for that blast from the past! i still remember vividly performing my own experiments with fdformat 1.8 (and pkzip) as a little kid back in the day, so that i could maximize the amount of games i could squeeze onto my floppies, because my 386's 80 mb hard disk couldn't nearly hold them all. the performance drop, the reliability loss (which i didn't know at the time to be caused by the extra tracks) and the tsr requirement ultimately deterred me from storing my entire collection that way though, as it made zip files spanning multiple (no-name) disks way too risky. don't want to lose a classic like monkey island or doom (which was ofc either thumbnail-sized or a slideshow on my 386) to a bad outer track! later, that story kind of repeated with overburning and a more tightly wound groove on cds...
I remember formatting floppies to 1.68MB back in those days. It was neat to do, but rather unreliable for long-term storage.
Also my first experience with Win95 back in those days was via 25 floppies. I got my hands on 95 beta build 359 and it fit on 25 normally formatted disks. Those were the days!
I remember formatting floppies that way too, back then...
Storing anything short term on floppy disks was not even reliable.
yeah I gave a copy of it to our IT department even when I was in college... told them I had the Win95 beta, and gave them a couple of boxes of floppies. I had to remind them after a couple of weeks of inaction that they weren't a GIFT so use it and give them back to me!
They really dropped the ball on that one... but the Windoze lab head was one of their less enthusiastic people anyways. I was an official beta tester for Windows Powerstation Fortran, which got me the actual Windows 95 beta CDs as well long before release - showing people the Weezer video (often the first decent quality movie anybody had seen on their PC) and watching them drool was always fun.
Less funny, installing a series of Win97 betas... and then they randomly renamed it to Win98 from one build to the next. :D
@@hewhohasnoidentity4377 yup, floppies were a step up from tape or punch card, but they seem seemed to fuck up often in crucial situations like handing in coursework
@@hewhohasnoidentity4377 floppy disks were very reliable, heck PCs in the 80s used floppies as boot disks, It's just that overtime the quality of each disk went down as the price went down, especially the 3.5" ones.
The same thing happened to optical media, new CD-Rs and DVD-Rs are susceptible to burn failures compared to their older counterparts as they're made more cheaply.
Because of the original PCs being so slow, the inter-sector gap was long to account for timing inaccuracies when writing. With a computer such as the Amiga which always wrote an entire track rather than single sectors, the large gaps were not needed. This allowed for 11 sectors/track rather than only 9 for a double density disk, or 22 for high density rather than 18 as with an IBM clone. The Amiga standard HD floppy had 1.76MB of space (880kb * 2).
Yep, and because it was "all software" you could then use something like DiskSpare to push that into 960/1920 using the same "non standard tracks'n'gaps" tricks.
I am also an Amiga owner, and I think the Amiga has the most flexible floppy disk system of all computers. Besides regular Amiga formats, it can also handle PC and Macintosh formats as standard, and can even be further customised if there's a need for it.
I remember to hassle of copying Amiga Disk Format (ADF) images to PC. ADF was 880kb and the Amiage couldn't read 1.44Mb disks, so I had to format them to 720Kb size and compress the 880kb fil to fit. That is how I manage to get all my saved games (and hi-scores) from certain games ported to PC and I still have them.
Pc only supported MFM disk floppy dikettes, Amiga floppy controller was fully programmable
I remember having a game for my Amiga called … Starglider II ? .. on that one single disk was both the Amiga game and Atari ST game. My thought back then was that since both systems were 68000 cpu based, as long as both could read the boot sector (so would have to be MFM to please the ST that used essentially the PC 720KB format.. let’s not split hairs about how early TOS tweaked it) then the boot code could figure out what system it was on. And with the ST single sided 360KB disks were the common denominator and all Amigas having double sided since day one, then the ST could load from just the common side and the Amiga load the 2nd side.
Anyone know anything more definitive? Was that a good conjecture on my part as a teenager back then?
You can also squeeze a bit of extra space by reducing the copies of the FAT from 2 to 1, which is fine if you don't plan on getting one of the copies corrupted. This halves the number of sectors lost to the FAT.
To help with speed, you can add the 'buffers' setting to the config.sys, increasing the number of sector buffers and allowing read-ahead buffers as well, which may mean the interleaved sectors can be put in the read-ahead buffer, allowing a track to be read in fewer rotations, eg
buffershigh=64,8
Also, see the 'smartdrv' command for speeding up floppy disk access. I don't remember if it was available from the w95 floppies or if I kept a copy from 6.22, but I would make sure I added it (with the 'A' parameter to enable caching + readahead etc for the floppy).
Man, such obsolete knowledge knocking around here haha I wonder if I can low-level format my brain to get this back?
Btw, the MS .cab file format used the Diamond compression/format which seemed so slow, I always figured the naming was because "Diamond's are forever"
Interesting! Thanks for sharing. There is so much more about diskettes I don't even know. I am completely blown away how many people are watching this video - so much for "obsolete knowledge".
smartdrv, that's a flashback! :)
I do this from time to time when I'm trying to write a disk that has just a couple KB more than will fit in a standard formatted disk. I don't usually drop the 2nd FAT (although I'm not entirely sure why I don't...), but I will reduce the root directory size to, e.g., 64 entries (which is usually more than enough), or change the cluster size from 512 to 1024, or even higher, if I'm trying to copy a driver installer that uses large compressed files. That, in effect, decreases the size of the FAT, giving you more room for data.
I haven't yet run into any trouble with any version of DOS or Windows that were offended by a disk that diverged from the way Microsoft's format tools do it (well... caveats...) The document floating around about the FAT format, from Microsoft, expressly requires compatible implementations to read the BIOS Parameter Block and do all of the calculations, vs. making any assumptions.
The caveats: Just for my own curiosity, I wrote some tools to read and write DOS partition tables and FAT volumes. I've used these from a Linux CLI to prepare hard disks, or images, for use in retro PCs. Windows (9x) will fail to install if you don't comply with _some_ expectations, like the OEM string for example. In some cases, depending on what you changed, it might pass the Scandisk check, but then the installer will fail. They're perfectly valid FAT volumes, but there are some trivial things up with which the Windows installer will not put.
@@bitsundbolts this was common knowledge for a programmer in the 80s and early 90s. this level of information was widely discussed in popular computer magazines like PC Magazine. References like Ralph Brown's interrupt list were freely available.
Interleave and sliding are all about having the right sector under the head at the right time. If you don’t have the right sector under the head when the drive is ready to read/write, the disk has to make another rotation, slowing data transfer.
Yep, interleave 2 means that to get to the next sector on a drive you rotate the disc 2 sector sizes, so the physical layout with interleave 2 and 21 sectors is: 0 11 1 12 2 13 3 14 4 15 5 16 6 17 7 18 8 19 9 20 10
This gives the installers one sector of time to process each sector .
Another trick from the old days now used on hard drives is to use larger sectors by reconfiguring the FDC in the computer without changing the standard TEAC compatible floppy drive that doesn't know about bytes and sectors, it just transfers the bit stream to and from the head .
Having installed Win95 from floppies before getting a CD-ROM copy, I can tell you that the floppy version contains only the stuff in the numbered CAB files in the main install directory, one CAB per floppy, none of the bonus software in other CD folders .
I'm actually surprised the DMF discs contained a file system instead of straight CAB files, but I guess that was needed for MS Office floppies under Win 3.x .
The 1024 cluster size was used on 320K and 360K floppies, so was already in the common floppy drivers etc. 320K floppies were the same as 360K, but 8 sectors/track allowed the entire DOS 1.0 FAT to be a single sector .
There were official tools distributed by MS at their old BBS, FTP and some MSDN disks. The name of the tool and ZIP file is called DIAMOND. The DIAMOND tool not only is used to create CAB tailored software installers, but also the DMF disks. CAB fileformat and Diamond DMF floppy format are meant to work in tandem. As you said, DMF isn't meant to be used in DOS, so Floppy 1 (Boot/MemManager and Boot Tools), and Floppy 2 (Setup and Precopy CAB) are standard 1.44 disks. Once Win31 Standard mode is launched from decompressed Precopy CABs and "graphical setup" launches, LZExpand.dll and its VxD will layer on floppy disk access, and Setup will be able to copy and expand from DMF floppy CABs safely. This is also why NT4 doesn't read/write from DMF Floppies.
IBM used similar strategy to distribute Floppy software in a fewer floppies. It is called XDF format. But unlike MS, IBM included the required tools built in OS, and while in OS/2, OS floppy driver can read the format natively. I guess PCDOS can also read XDF (no boot), as PCDOS floppy 2 and onwards were XDF if I remember well.
how simple compression software simple🤣
DIAMOND later change its name into MakeCAB
I had no idea you could do this. I have fond memories of the floppy years, thanks for this, I would love to see a video comparing both Windows 95 versions.
The Linux "fdutils" package included a program called "superformat" which allowed formatting standard floppy disks at up to 1.992MB (I believe using mixed sector sizes). The downside of larger sectors is that if a sector goes bad, you lose more data.
As I said on my comment, i remember sharing games using disks formated to 1.8mb. So it was possible.
Amiga using standard FFS could write 1.79 MB on a floppy. With Custom FFS, you could write ~1.9MB.
Extremely good video. True jewel. Great work!
Nice video! This took me back. I was 20 when Win95 came out but before that ran a BBS using DOS on a 286. I remember so many nights sitting inserting floppies. 🙂
Fascinating video, and never realized the official Win95 floppies were different in size. The one copy of Win95 I had on floppies was created via a utility on a Pac-Bell system. Now I wonder if the utility did this in the background for the other disks besides the first couple.
When I was working at the computer store back when I was in high school, one of the technicians was pretty crazy. He was obsessed with getting the smallest possible Windows 95 installation that will boot into the GUI. He managed to get it down to less than a single standard floppy disk, and it still booted into the GUI. Absolutely insane.
Most of it is "support for something". If you strip out "something" then you can strip out "support for something". If you have "in built" file system compression it let's you go even crazier. The old QNX Demo Floppy is probably the hallmark of it, but they were "sort of cheating" because QNX was designed to be modular from the go so stripping it wasn't all that hard.
@@ErazerPTthat qnx demo impressed me as a kid 😂
@@ErazerPT Yeah, pretty sure if you tried to use it for anything useful, it would refuse to do it or just crash.
@@ithecastic Obsessed, yeah that probably wouldn't have been too bad. Lack of social skills, sure lots of people have their personality quirks. But then he'd occasionally say something that was obviously meant to be "funny", and perhaps I (a 15 year old kid at the time) won't take him up on his offer to hang out at his place on the weekend.
I feel like that dude would love the modded windows community
I saw this video 25 years late.. I have copied MANUALLY all the files I could fit from each image after disk2 to a standard formated 1.44MB disk thousand of times because I didn't know how to fit all of them at a single disk, hence it usually took me hours of work and copying-pasting files from the image to the disk and vice versa..
Veryinteresting video, all my life I thought these were "special disks". It brought me a lot of memories of the past. Thanks!
This is really cool! Thanks for the explanation. I always wondered how they'd done this. From what I understand - a lot of the sounds were cut, as were the background images and mouse cursors. Also there was usually a folder on the CD with extras in, such as videos and games which might explain where the extra space was used up.
Great stuff, I rarely subscribe to the channel after watching one video so you can be proud of yourself.
Answering the question at the end of the video, I would love to see a sequel.
The additional tracks are closer to the hub in the center of the disk. It's risky to store information there, both because there's less area in which to store data (the disk rotates at the same angular speed, but the heads travel less linear distance in that angle, so the data is packed together tighter and may not be stable) and because some drives' heads physically cannot move there.
They say if you can't explain something in simple terms, you don't understand it. You clearly understand it :) great video.
As another user commented the versions are the same between the CD and Floppies. What you do not get in the floppy version is any of the extras. Both versions however have the same number of cab files which is what is used to install windows. Cab files are just compressed files much like zip files.
I guess a lot of the CD ROM is filled up with the music video by Weezer?
Wow! Thanks for the compiled FDFormat share!
This was a great video. Now it makes me curious how much extra data you could store on a 2.88mb floppy disk! I would love that video from you!
I'd almost forgotten about DMF - thanks for the refresher!
I remember to hassle of copying Amiga Disk Format (ADF) images to PC. ADF was 880kb and the Amiage couldn't read 1.44Mb disks, so I had to format them to 720Kb size and compress the 880kb fil to fit. That is how I manage to get all my saved games (and hi-scores) from certain games ported to PC and I still have them.
This was awesome! I have a vague, dusty and hazy memory of using FDFORMAT somewhere around 30 years ago - this was a great blast from the past!
I was in the Windows 95 beta group. I was unable to successfully install Windows. Some received the CD. They sent me the floppy disks. Spent nights with a Microsoft engineer often working until 3AM in the morning. They finally asked if I would agree to ship my PC to them. The problem turned out to be an old floppy controller. They would not confirm but I believe the problem was reported in the wall street journal. I know they were scared. Fortunately my issue was rare and their was not a flood of failed installs.
Ahh, the good old days of trying to squeeze every little bit out of the media that we could. At some point in time ~25years ago or more I was formatting a lot of my "data" disks this way using tools like 2M that were closer to magic than to code, not only messing with floppy/drive parameters in the "official" way, but also injecting code to the bios and such. It was nice seeing 2M even mentioned remotely here (on the related articles, wikipedia page). Some of those disks still exist, and now I have to wonder if after all this years and (ab)using those unsupported cylinders at the end, they can still be read properly or not. Gotta try someday. Great video, wish I could show it to my younger self to answer the oh-so many questions on this topic.
2M worked unless too much tweaking. At least for 8 years. Never had a problem. Found 3 diskettes 20 years old. Nada problem.
@@sveinungsandsbakk416 I have some floppies from around 95, all the regular 1.44 disks are still readable, but none of my 2m disks are readable today, which is sad.
@@gacsizclickon Yeah, the tolerances are tighter for those exotic formats -- which is specifically why they weren't the norm. The actual disk isn't structured any which way, it's just the controller and, to an extent, the drive's physical and electrical capabilities that really define how many bits you can squeeze in there. The compromise is how compatible and resilient you want it to be. :-)
30 floppys for the version i got. My Father got me a 486 cnc work computer and it had only a diskette drive, then my school got Windows 95 on disc and way of copying it on diskettes. Took those home and installed Windows 95 on my machine, what a great windows. Thanks for sharing, i didnt know the original diskettes had 1.68 mb of data.
I loved the sound of floppy disk drives
Different drives had different sounds so what you loved would depend on the machine/drive.
I always loved the sounds of the older ones that were, well, noiser. It was almost as good as the sound of good ol' dial-up.
There's a little add-on thingy for PC mobo that can simulate HD sounds. not quite FD. But its something. Attach to HD power light and it "clicks"
For me It has been so many years since anyone mentioned interleave. Kudos.
Yes, I would love a video with the additional details, please and thanks!
I was really happy when I discovered "FDFORMAT" which was a set of two programs (the other being called "FDREAD" and was a Terminate And Stay Resident or TSR program). It allowed you to reformat floppy discs to use 82 tracks instead of 80, use some of the gap space for extra sectors per track and to reduce the number of root directory entries which would leave the sectors normally used for the root directory free for data storage.
The funny thing was that some formats, such as reducing the number of root directory entries, were compatible with Windows without any other programs needed. Only the more "exotic" formats required FDREAD to be installed in order to allow Windows to read the disc successfully. If you wanted to get a large file onto a floppy disc which was just a little too small for the file, reducing the number of directory entries might solve your problem.
In some ways, it's a little disappointing that we now have so much storage space available that we no longer need ingenious innovations like FDFORMAT to squeeze that "little extra" out of our hardware.
File system compression is still a thing! And in some cases can improve rw performance because the cpu cost of (de)compression is negligible
@@forbiddenera this is actually underused quite a bit. People always assume that old CPUs would be struggling with decompression too much.
I was really surprised when I tried a compressed executable on an Atari portfolio, running a 4.7 MHz 8088. The program loaded noticably faster when compressed
2M and 2MGUI were also fun to use with compatible drives and disks. This rapidly improved my understanding of error-correction techniques too, which made it even more fun to max out the sizes 😅
edit: Also, OS/2 had XDF and XDFCOPY for making almost 2MB disks, but was built into and part of the OS/2 Warp installation from floppy’s.
FEC forward error correction with 2MGUI, and then I used a jar dos compression program that was like LZMA, not to be confused with java jar files.
I get more than 2 MB of free space (more than 2097152 bytes) was very fun to made this disks and was realiable
Oh yes. Being a big fan of OS/2 Warp back then, I've made the XDF my "format of choice" (even though using it for everyday storage wasn't straightforward); years later, when it came to copying / backing up my old files from these floppies, I regretted it profoundly 🤣
@@LoftBits And so it was with every non-ubiquitous format. haha I've learned that lesson more times than I would care to admit. There was quite a while there where I would yell at my former self, saying "I don't have anything to read UC2 archives anymore! Was it REALLY imperative to save the extra 1KB over a ZIP file??"
And then I did it again, with a lossless WAV compression utility called Charlie Packer. There was exactly one program that could read those files: Charlie Packer. I think I *still* have c13 files on my NAS somewhere...
I think the interleave parameter is for a physical phenomenon: the floppy spins and as the system processes the data from the sector currently being read the disk spins unter the head. So to get a continuous stream of data it would be good to not wait about a full rotation until the next sector comes along again but store the next sector a bit later on the disk.
So imagine 4 sectors on a disk, you don't store 1, 2, 3, 4 but more like 1, 3, 2, 4, this way you have a one interleave.
I think it works that way and I hope that explanation makes sense.
That is exactly why it's done. However, an interleave value of 1 actually means that there is no gap at all. The number basically tells you how many disk rotations are needed to read or write one full track.
Still, it's weird that DOS couldn't read interleave 1 disks at all. It should just be slower.
It was mostly a benefit for older PCs that might take enough time between finalizing reading 1 sector and preparing to read in the next. An interleave gives it more time between that. If not given that time, it would need to wait a full rotation to read each consecutive sector, or if its timing is especially strict, may even time out or something before it reaches a full rotation.
Very interesting. I was using VGA-Copy for this purpose, but I never knew how it worked :)
BTW Not all floppy disks could handle 1.7 MB format, I had to test every one and mark those that didn't.
Thanks for explaining this little old mystery :)
I had vgacopy as well. Nice tool.
Super interesting video about floppy disks! Always was a fan of them, but was born way too late to experience them. Great stuff man!
You have answered a long time question for me. Thank you
Increasing the track number is pretty much the same as when you overburn a CD-R, it will record further into the external margin of the disk, which in the 3.5" floppies can actually cause mechanical issues with some older drives and on those if you keep doing it you will kill the drives mechanically, one of the rare occasions back in the day where software could actually cause physical damage to hardware. Prior to overclocking that was next to impossible.
You can't damage a drive by using it, except long-term wear to end of life.
It was just increasing the density. 1,44MB was set to the industrial standard. It was considered the most efficient quality demand at fabrication of disks. Anything beyond it was approveably unreliable.
@@manuell3505 If you tell the drive to seek to e.g. track 90, it can't really do that. Either there is a safeguard preventing stepping beyond a certain point, or you simply crash the head onto a mechanical barrier. The second option will at least result in a misalignment of the head, which in turn will make your drive useless. That's not only tear and wear.
Except that in floppy disks the tracks start at the outer part, so the additional tracks are on the inner margin.
I bought this when it was a shareware program back in ‘88 from a 7-11, quite a fascinating program though wow you really put it through its’ paces
Love your voice and detailed content
As I recall, the 13 floppy disk version of Windows was lacking a number of optional components, such as additional sound schemes and system tools (the Windows 95 CD--early OEM release--I have at hand has a utility to create a custom install script). Note that the initial release of Windows 95 I have only supports 8.3 file names and shipped with an FDISK executable that only supported FAT16, a later OEM CD I received from Microsoft after market-release has a version of FDISK that supported FAT32.
The german disk version of Win95 that my roommate bought at the time consisted, of 78 floppy disks.
He bought it because it was ten Deutschmarks cheaper.
We laughed at him for weeks...
Don't forget about Weezer
@@Epic_CWeezer!
@@Epic_C Plus Edie, the weird animation by Bill and Havoc! IIRC
Amiga could write 1.79.MB on the same floppy standard, so 1.68 MB weren't a problem.
The filesystem you use decides how much you can store on a floppy. The floppy itself can store up to 1.9.MB or something and it doesn't matter if it's done on PC or Amiga.
We did install Windows 3.1, Windows 3.11, and Windows 95 using floppy disks when they first came out. People had HDD yes, but only a few had CD ROM drives. So there was always someone on the college campus who happened to have a plastic bag full of such floppy disks and went around spreading the love among us :D
The theory of copy protection was already absurd at the time because you could also get Windows 95 on 5.25" 1.2MB floppy disks and copy their contents on 3.5" 1.44BM disks with standard format, instead of 13 disks you were going to need 21 but if you weren't going to pay for Windows 95 you had a lot of money left over to buy floppy disks.
Ah yes the good old DOS formatting days. Back in the day i randomly found the 2M formatting tool & discovered that the quality Teac floppy drive i had could format quality floppies to the largest 2 million bytes (aka 1,97kib i think) extended format. of cause you needed the 2M driver software to access those larger formats as it wasnt natively supported. Most of the backups i did was with the slightly smaller 1,8 or 1,9 sized formats to be on the sure side. Sadly the quality of floppies dropped with time & it was really sad in the end where you could buy a 10 boxes of of 10 floppies each & you had to trash half of them because every other failed to even format to normal dos format immediately. Of cause the price had also drop to a point where they was nearly giving them away for free. Good happy times thou :)
I remember as a kid, I was able to format 5.25" HD floopy disks to 1.6MB instead of 1.2. We used Dos Navigator, and it had this option. As I remember, it worked only with some disks which were in really good shape, and it was not too reliable.
Yeah it depends on the quality of your disks. And probably the drive as well. I got the 5.25 ones mostly to 1.4MB.
Bit of trial and error, then dump data on it and verify that it can be read correctly before usage.
i just love everything in this video
I've made the install floppies for Windows 95 manually using Linux and pulling the cabs off a Win95 CD. It was an learning experience about how floppy drives work.
A lot of stuff on the Win95 CD is extra stuff too. They had music, themes, music videos, and Hover on the CD I had.
I can remember the first-time installing Windows 95. I was about 11 or 12 years old. Lots of Floppies. Tons. It took forever!
My Acorn used 1.6MB on floppy drives too. Good times...
Ah, memories I remember setting in my chair with my chips, Mountain Dew, and watching TV installing one disks after another clicking the continue button (its been a long time). The 1st time I was excited, the 15th time mad with my head on the table wishing this was faster. Thanks for the memory's
A video about floppy disks in 2023 with 58,000 views and 346 comments. Amazing. Geek score 10/10.
The only thing missing in this video is an explanation about how increasing the number of tracks / sectors per track actually physically results in a different layout on the disk compared to the conventional 1.44 MB layout -- that space has to come from somewhere and not every viewer is going to have an intuitive knowledge of the layout of cylinders/tracks/sectors.
I worked at a computer store when 95 came out. Almost every computer had a CD drive at that point. Few had CD/RW drives, which may be the confusion in the video. I can only remember installing 95 using floppies a couple times of all the computers we built / sold.
Now, 3.1, that was usually on floppies, and it was a pain in the butt.
A large portion of pre-existing PCs that supported Windows 95 did not have a CD drive, and that is what the floppy disk distribution would best serve.
Also I think perhaps you're thinking of Windows 98? Most new consumer PCs would have a CD-ROM drive at least as an affordable option late 1995. However CD recorders were still very expensive at this point (>$1000) and not typical and CD-RW would not exist for several years.
@@oogieboogie232 - You are correct that CD-RW drives were very expensive at that time. I think we were getting them for about $500 each. I don't know what we were selling them for, since I was doing PC builds at that time and not on the retail side of the business. We sold very few systems with CD-RW drives in them. But, we put CD-ROMs on almost every PC we put out at that time. We bought in bulk and paid wholesale, so I think we were getting them for around $100 each for the drive and the controller board (again, not sure what we were charging retail). We were primarily in the business of building new computers and doing hardware upgrades, so we very rarely did OS upgrades, and when we did it was usually for business customers, so they were using NT and not 95. I was only doing that from early 95 to late 96, so I know I didn't deal with installing 98 while there. After that, I went to work for Honeywell, and only delt with NT & 2000 there, and didn't deal with any consumer versions of Microsoft products.
I definitely remember installing Win95 from floppies on 486DX40 PC
@@henson2k - Yes, it was done, just not as prevalent as this video would imply. Pretty much exclusively only on systems that didn't have an internal or external CD-ROM drive, and almost always for home users to upgrade their OS on already purchased systems. When we built systems that didn't include a CD-ROM drive, if we had a CD-ROM drive laying around we'd hook it up to do the install, then take it back out of the system.
A lot of PCs back then had CD drives but not all support booting from CD, even up in to the XP era it was common to initially start the install from floppy to get the drivers in place for the CD-ROM.
This is an incredible find! I wish I had this much data when copying around MP3s and high res images off my Mavicka camera. The possibilities!
It was a very small window of time when higher capacity floppy formats were a thing. 100M Iomega ZIP disks kinda replaced it for a short time, until the Click-Of-Death made them unreliable, but by then, CD-RWs and flash drives had replaced them.
@@FlopsyHamster I think that capacity woud have worked all the time , it is just strange that it was not included into default format utility
@@deltaxcd I think there may have been some compatibility issues with the format. I don't think all floppy drives and/or floppy controllers could support it.
I had a client at the time who wanted to upgrade a brand new computer to Win95 with floppies, and it didn't work. The floppies read fine on another computer, but not on that one. I wound up copying all the floppies to the hard drive on another computer, backing up the install files onto 15 or more blank floppies with PKZIP using disk spanning, restoring the files to the new computer's hard drive, and installing Win95 from the hard drive.
This same computer was not able to use the built-in backup routines in Simply Accounting, a very popular accounting package, to back up to a floppy disk. The backup would always fail. I discovered that disabling the floppy disk driver in Win95 would revert to reading and writing through MS-DOS, which would allow the backup to work... until the driver would randomly re-enable itself. In the end, I had to set Simply Accounting to back up to the hard drive, and I put a batch file on the Win95 desktop to copy the backup to a floppy disk. This did not please the client at all, as it was an extra step, and they felt I should be able to get the program to work as intended. I lost a bit of my "miracle worker" reputation due to that stupid floppy drive.
I always thought it was a bit ironic that floppy drive and controller compatibility started to become an issue at the end of the floppy drive's lifespan. Usually compatibility issues arrive at the start of new technology, and work themselves out.
@@FlopsyHamster from the video, it sounds like you could get higher capacity in regular floppies from even the early 90s.
I remember being so excited getting w95, and was not disappointed
17:30 On the outer edge of the floppy. You can verify this by taking the lid off the drive and watching the heads as the drive formats the disk.
Fascinating. I'm also curious about what was cut for the floppy disk install of Windows 95. Maybe it was drivers? Or that promo movie I remember being there where the showed the old Windows 3.x desktop fading away into the clouds?
I think I know what you mean. This video was in the OOBE folder on the CD-ROM if I'm not mistaken. I wondered about the abbreviation of the folder name that time - and there was no internet yet to look it up.
Later, I found out that it means "out of box experience".
Anything that wasn't in the win95 directory wasn't included. In addition, some of the accessories were also missing, Microsoft used to have a download on their FTP server which added the missing components back to a floppy install.
I used to use a disk doubler back in the day, allowed me to format a 1.44Mb floppy as a 2.88Mb floppy. The resultant floppy didn't work in every computer, but those it did, boy was it a lifesaver :)
1.76MB was standard size for Commodore Amiga HD floppy drives. I have original win95 and office install floppy disks. I set up win95 under emulation on my Amiga. It worked but was really slow, even with a 68060 accelerator card.
While I had a HD floppy drive on my Amiga 4000, 90% of my floppies were the standard double density ones with 880kb on them! 720kb was for peasants 😅
Thanks for the video!
WfW 3.11 was my last floppy-based installation.
Fast forward 25 years, bite/cluster/sector geometries have morphed into an unexplainable mechanistic methodology when you write a file on an enterprise SSD.
While sometime confusing, it is possible to figure out the geometries of writing/reading floppy disks and hard drive, but I just had a bad time when I wanted to discern the inner working of a multi-chip flash drive controller, where multiple optimisation and reliability algorithms crosses together...
And that's one of the major reasons (there are many others) why it's so much harder to recover data from SSD's than it is from magnetic hard drives.
CABS are also highly zipped.
Pushing this floppies this way, give more reliabilty issue, thus data errors,
These floppies were natorious for errors and failure when using them.
CD version has the Windows extra tools and the bloatware videos.
Great video! Fun to watch. I've used FDFORMAT but I never really understood much about it. At the time, I was trying to get 1.8mb floppies working, which I think also required a TSR? I can't remember.
I remember that I used 2MF to format 1.44MB disks to have 1.88MB on them (1,931,264 bytes). It required 2M, a small TSR driver to work because it somehow fooled also the floppy controller to make it work in a really unusual way. It was not just surprisingly stable but also really fast as it optimized the arrangement of the sectors.
And the bonus part: every formatted disk contained the driver hidden in its boot sector so it wasn't even a problem if you forgot to carry 2M on a regularly formatted disk to your friend. It was enough to boot on the disk and the driver loaded itself automatically. I discovered it accidentally when once I forgot removing a disk from the drive.
Interleave generally give the milliseconds in delay that the controller needs to react to writing data. It depends on the IDE bus and bus system and what is more appropriate. HD density disks have 2MB and can be formatted with 1,6MB DMF format. The cuts were just tools that were related to Ressource Kit and other add-ons such as Hover etc.
You know this is going to be a good video when within 5 seconds is Vindows95
I remember installing Win95 translated to the Czech language from 28 diskettes many times, fun times.
That is half a day of work right there 😂
Interleave: after reading Sector 18 on track 1 the disk spins while the head moves to track 2. To read sector 1 on track 2 the disk needs to turn until sector 1 arrives again, which is 95% of the rotation. By placing sector 1 on track 2 next to sector 2 on track 1 you can omit that wastefull time of rotating 350 degrees. Depending on the speed of the read/write head the optimal interleave can be 1, 2, 3 or 4. The time rotating the interleaved sectors must be slightly larger than the time it takes for the head to position on the next track.
Very interessting. My 13y old me went straight to doubling the size by drilling a whole into DS/DD disks :)
Very informative. Thanks for sharing!
My Aunt brought a copy of this home from work, It was either Thanksgiving or Christmas, I sat at her desk, didn't even turn on the PC:
I opened the box & saw the amount of Floppies! "THIS MUST BE EPIC!"
Great video, good research....more of this please 🙂
Thank you. I remember pondering this "WTF?" The BIOS screen sure brings back memories :)
I am glad I learned all the DOS commands as a kid as there are still some uses like BIOS and hardware firmware
Loved that "Marketing Formula" back in the day too change base 16 to base 10. "Thanks guys..."
Interesting video and decent presentation.
I think that on CD version there was an intro movie copied and displayed upon first user logon right after installation. There was a C:\Windows\Media (or something simmilar) directory with this movie and it was the first place to look for lost disk space.
I vaguely remember Microsoft's installer failing to continue when ran from copied diskettes, despite them being cloned from the originals for backup purposes. Analyzing the first few sectors, I noticed an identifier of sorts that was different on the originals vs the copies. (It was "MSDMF" or something...). After manually changing it on the copies, the install was successful. EDIT: It was the FAT ID that was different. Windows 95 OSR2 was checking for "MSWIN4.1".
That's right. Win95 was developed as Windows 4.00, and many of the internal filenames reflected that. Logically, OSR2 was therefore Windows 4.1.
Brings back memories, I was able to back the floppies up I remember lol.
I remember using 1.68 MB formatted diskettes around year 2000. Of course CD ROMs were abundant but this before I had a CD-RW drive or USB flash storage was around, as well as fast Internet, so data transfer was possible mainly with floppies. I routinely used multi-part RAR archives, and every extra 200K went a long way.
I was still using floppies back in 2005, I live in south america, so tech is very expensive.
@@LagrangePoint0 I think I got my first 128 MiB USB drive around 2003. I lived in Astana, Kazakhstan back then.
@@veschyoleg Astana looks like a nice place (at least in pictures), where do you live now?
@@LagrangePoint0 Astana is a nice place to visit but not a very nice place to live: extremely cold and windy winters, very hot and dusty summers. I live in Almaty now, summers also hot but overall much more hospitable.
I’ve been to Chile and Perú on business trips, unfortunately no other South American countries.
@@veschyoleg Well, if you ever come to south america again, avoid venezuela AT ALL COST. Btw, what do you do for a living?, what kind of jobs are available over there at Almaty?
I remember messing around with floppy disk formats 30 years ago on my Atari ST. I found that I could format the disks with 82 tracks 10 sectors, that's half of what your HD format, but those disks couldn't be read on an IBM. I also made my own personalized boot sectors.
As for interleave, on SD diskette, an interleave of 2 was faster than interleave of 1. It's down to how fast the disk spins compared to how fast data is transferred from disk to computer. This is also why an interleave of 2 is slower than 1 on HD diskettes.
I have the windows 95 floppy disk set, I think mine is 27 disks for the extra features. Interesting to install. You boot on the first disk, but you get an installation GUI after only the second disk!
When my 20 MB HDD died along with the controller (released A LOT of magic smoke :) ) I looked around for "bigger floppies. I used HD-COPY by Oliver Fromme that played around with tracks and sectors without TSR, for me it made the most "stable" for normal read/write use disks back in the day, quite larger, and it would also "revive" "track 0 bad" disks at least temporarily. Then with TSR I used 2M a lot, the standard 2M format ones were quite reliable, the "guinness" ones were more finnicky.. Fun times! I could play Leisure Suit Larry (I think 3?) installed on those larger floppies, as it needed slightly more than 1.44 space to install :)
I remember DOS Navigator has also an option to format floppy at 1.68 MB. And I used to format my FDs with that tool to got some space more, that was useful with playing around with WinRAR, that can make its archives with automatic volume size, detecting it when accessing to a volume. But when I installed i guess Windows 2000 of ME (can't remember now), i found out the 1.68 floppies cannot be read under that system. It appears just like unformatted disks.
1.76 MB, used it a lot. Worked like a charm.
Interleave is sector ordering: With interleave 2 a track with lets say 4 sectors is written in order 1,3,2,4. So the computer reads sector 1 and has time to process the data as long as sector 3 is under the head, then it reads sector 2 and uses the time sector 4 is under the head to process the data, it continues to do that with sector 3 and 4. So it needs 2 revolutions to read one track. If you use DMA and don't use buffering then you don't need time to shovel data around. Then you can read directly to the desired address in memory using interleave 1 which is two times faster.
8:34 looking at the See Also section and seeing the [2M] fills me with nostalgic feeling, I use that a lot before I finally upgrade to FAT32 capable windows.
I would assume MS used some sort of compression in those CAB files on the floppy disk version compared to the CD which may have not had any compression.
Otherwise, the CD version may have been for newer computers, so the extra space would've been drivers, and the floppy version would be for older hardware where the drivers were more limited.
Windows 95 CD also had that Windows 95 Plus crap which had extra themes.
Yes, the CAB files are actually custom compressed archives (either ZIP or LHARC format, I can't remember). I used to repack them to fit custom sizes back in the day. It all escapes my memory now though lol
It’s actually enjoyable formatting with floppy disk back in the days. Back then system gets really slow after a while. Reformatting with floppy disk gave a super excitement about getting the pc in decent speed again. Then… Warcraft, Diablo, descent, StarCraft, and alot other games are all standing to be install next xD
Regarding the question at the end, I think the CD version is so much bigger because of all the included drivers. The floppy version just installs the operating system, while the CD version can help configure your system (key word "can").
A reduced driver library crossed my mind as well. They did have some music videos, game demos, and some Microsoft Marketing material on the CD-ROM, but I do believe, like you, that there have been more cuts here and there.
@bitsundbolts I hadn't considered the multimedia, that's probably a pretty big chunk of it.
Great vid btw!
Thank you!
I had a retail version of 95 on floppies and it was some months before I got a PC with proper drivers for it. I remember going from using it with 16 colours to the full range and the startling effect of seeing pictures and websites as they were meant to look.
NEC made a 1.44M floppy drive with a linear actuator to move the heads. It was super quiet, only made the tiniest of *eeep* sound when accessing a disk. I should have kept the one I had because I've never seen another one.
I had a tool for creating DMF disks. It included a patch that was placed in the MBR to act as a disk reader controller.
In addition to everything shown in the video, I managed to have a Windows 3.1 installed on a DMF disk, which was later compressed using drvspace or doublespace, creating space for a trimmed but functional Windows 3.1
"Win3.1 on a floppy", the ancestor to the now more familiar "Windows/linux on a flash drive".
Wouldn't surprise me if within the next few versions of Windows, Microsoft combines the fact that it can detect when something's a USB flash drive, with the want to prevent copying of the OS without payment, into the inability to install Windows to any type of removable media.
I remember multiple configurations and utilities in the times of MSDOS. One very famous was FDFORMAT. The resident allow it to use formats that should be allowed (but not) by MSDOS, 512 sectors based, and increasing tracks. Almost all floppy drives of the time allowed more sectors per track and up to 82 tracks at least, although most units supported even more tracks (some 84).
Other was 2M, that besides provide an alternative to FDFORMAT format support, that allowed a mix of different sectors sizes, while the resident faked MSDOS make it thinking that it was just multiple 512 bytes sectors. That configuration allowed even more equivalent (now virtual) sectors per track.
I modified this utility to myself (I met "Ciriaco", the author, personally, in the university), supporting an even bigger sector with a configuration that support even a bit more.
All these formats where supported in Linux through the "superformat" utility.
And, just as last, the "2mGUI" utility. It used a one unique sector that it was TOO BIG, and used the trick of reset the controller to force the floppy to don't override itself. That was the utility that was able to write a floppy to the maximum capacity. But the problem is that write required a precise timing and talk directly to the floppy controller what was almost unable to be adapted to windows and linux, so that format was used exclusively in MSDOS with the same utility.
As a curiosity, using superstore (real-time compression-decompression of a virtual filesystem that emulated a FAT) + 2M, was able to create a one floppy version of Monkey Island.
Computer tell tale of an old man on the times where Internet where a (mostly) lab thing and floppies reign supreme between people X-D
Now you can play in a browser that run a virtual machine over another virtual machine to run a "DOS" and download all of this from "Internet Archive" with a search and a click.
You should have seen the size of the Software Developer Kit (SDK). It came in a box bigger than a microwave oven and the manuals filled a whole bookshelf.
*laughs in VMS/VAX* ;)
In the good old times I did a mod to multi-i/o card that includes 27 MHz oscillator and a 74xx chip, I don't remember what one, allowing to switch between 27 MHz and the original 24 MHz. The input of the contraption was connected to one bit of LPT2 on the same I/O card. Another LPT2 bit was connected to the 5.25" drive itself, allowing to change its rpm from 360 to 300. The contraption was invented by one of my friends, a computer geek, who did several other crazy things including cooling the overclocked 486 with a glass jar filled with water, placed, lid down, on the CPU.
This mod allowed to (1) format 18 sectors on a 5.25" HD floppy, so it can replace much more expensive 3.5" (2) format 15 sectors on a standard density 5.25" floppy so they can replace 5.25" HD, (3) using a custom written formatter, format both 5.25" and 3.5" HD floppies to about 2.1 MB. The main motivation to do the mod was about 500 5.25 SD floppies I had on the desk that became usable again.
Thankyou for charing the information.
Once I used a tool which formatted different sector sizes on the tracks. IIRC 5x2KB, 1x1KB and 1x512Bytes on a track, of course special driver software required to operate such floppies, having virtual 23 sectors per track.
This converted the gaps between sectors into usable space. With 82 tracks this resulted in nearly 1.9MB of space on the floppy. I still wonder if there was an option to reduce the numbers of FAT to 1.
I remember messing about with (IIRC) LLFormat to create diskettes that could hold 1.92MB of data, but they had no FS on them. I used them with a friend of mine to transfer large games by putting the game into an ARJ, then tarballing the ARJ into slices and writing the raw tarball to the 1.92MB diskette. Then reading the raw data back from the diskette in order to open the tarball and unpack the ARJ.
Upside of this was that it needed less diskettes, downside was that you needed to be able to store the data at least twice on your HDD, as you'd need to unpack it twice.
In the end we managed to source a second QIC-80 drive, which was much more convenient. Sure it was slow AF, but it'd hold 40MB on the short tapes or 80MB on the long ones, double that because we had identical drives and could use hardware compression. It was kind of awesome having teachers in school be all confused about what these QIC tapes were, but also less awesome that both of us got sent to the principals office because some teacher thought we had stolen a tape from school. Thankfully the IT guy in our school was awesome and would be more curious about what we did with said tapes than where they came from. Also the school used DLT for its backups, so their tapes weren't compatible in the slightest with our QIC tapes.
Ooh the benefits of having a father who worked at DEC. Also, yes I still have those tapes, yes one of the drives does still work and last time I checked the tapes were all still readable. But then again that last time I checked was to gather the data from tape and store it on less-than-reliable CD-R discs, most of which have since died to rot.
"Using the marketing formula" 1MB was originally 1024^2 bytes. MiB is a later invented term for 1024^2 so that marketing could use 1000^2 for MB to shrinkflate their drives. This even resulted in successful lawsuits for deceptive advertising, but in the end industry permanently changed the language.
Amiga disks DD also had 880k instead of 720k.
The rare Amiga HD disks with 1760k instead of 1440k on the same disk.
IIRC the Amiga high density drive for the A4000 spun the floppy at 1/2 speed, to keep the data rate the same as before, because the floppy controller and audio chip (Paula) was never upgraded from the original A1000.
There was a difference in readability of standard 1.44 floppies formatted with different settings. They would often not be readable past about 75%. I think that, when invoked from Windows, the timining of the format wasn't stable. Sounds from the drive came at slightly irregular intervals. DOS Navigator had options called "forced" with "optimize" that made a previously defective disk work again, even when later written from Windows. I think optimize might have involved sector shift.