When I was 10 I copied what seemed like 100 pages of BASIC code from a philips msx manual into the computer, resulting in a launchpad popping up on the screen, launching a rocket into space. We all had various degrees of weirdness back in the day (and even still today according to my wife)
My kind of club. I remember taking a family road trip around 6th grade, kept myself occupied with a thick Serial Communications book and the user manuals to OS/2. My mom still talks about how my grandmother would look back at me with a confused expression and ask, "what is he reading..?" 😄 The only thing I regret is that there wasn't more detail about how the Zmodem protocol worked under the hood. hehe
as a kid hard drives were my passion too...great pleasure when i could llf and recover a dead drive..then i ran all kinds of disk utilities on it, msdos scandisk, norton 4.something and others i cannot remember anymore. apart from the old mfm and rll's, old WD caviar series were my favorite IDE drives both the silver ones but especially the black ones up to 500mb they were bulletproof
Wonderful video you've really gone through this nicely. I have six MFM's and three RLL's here at home in use in my collection. Really enjoyed this as I've gone through this journey more than a few times over the decades. :)
I learned this the hard way when i whas young and selling xt class machines. I had a teacher who whas in charge of the informatica systems of that particular school, and he had a room full of xt class machines that wher decommisioned, and since i had a great friendship with this teacher, he told me that those machines needed to be thrown out some day, so i asked if i could sell em, we ended up asking the prinicipal and he said sure, i could keep 1/3th of the selling price per pc, so i got to work, and they all used this kind of hard drive! Its insane how long it took me to figger out how to properly set them up, i ended up selling over 200 pc's for about 5000 belgium francs each (it whas a long time ago), so i made a good amount of money from those machines, i spend HOURES low level formatting xt machines! Insane how long 1 pc could take to format a hdd! How bigger the drive, the longer it takes! I had sometimes 6 pc's in my room all low level formatting at the same time :p insane how the times have changed man! Great video! Love this stuff!
My memory back in the day was that we were so happy when an mfm drive would reformat on rll. i ran a seagate 20 meg mfm disk on rll for five years with no issues. I remember lots of drives didnt work and lots did. My seagate was a half height model from about 1987.
That's right .... I once did it by accident, hooking up an MFM drive on a RLL controller and was so confused why my 20MB drive had 30MB after formatting.
I totally forgot how I used to do this. Thanks for the refresher. It's only been thirty years? Dang! SATA is a blessing. I see your monitor is as dirty as my test monitors. Great video.
This one was a special case, it was the 20mb basf drive being formatted by an RLL controller that was configured to use 17 sectors / track. So you end up with the same capacity as you would with MFM. Some RLL controllers allow you to set it like that for compatibility reasons. But the bad sectors were the result of the RLL encoding. If it was setup to use 26 sectors it would have formatted to 30MB.
I have a Type 1 just like here, with 0 bad sectors. I was blown away when I formatted a near 40 year old hard disk and it came up perfect. I promptly installed DOS 6.22 and Windows 3.0. I think I have 1.5 Mb free ;)
Rll encoding was possible on almost all mfm drives. The key to doing it relies on head position accuracy. Some drives were more accurate than others. This gave a lot of rll formatted drives the reputation of being not reliable.. eventually this wasn’t a issue. But the damage was done. The conner drives were great with rll. The rll format gave a good performance increase. A lot of 30mb drives were rll formatted 20mb mfm drives.
As from my experience, and as I comented a minute before, the adaptec ACB-2072 only needs to be used with custom settinfs and a longer step rate to let the heads and mechanics settle. I'm using 70 micro seconds on and very old, so called MFM drive with no issues.
Bad sectors on these drives are common from the factory. What you do have to watch out for buying second hand are lots of additional hand scribbled bad sectors, one or two is fine, but I've seen drives with multiple post it notes full of bad sectors listed.
Cool. Learned a bunch. I have a number of mfm drives that need attention. Did not know these specifics. They probably won't work anyway but I can test them better anyways.
You know something I don't ? :) Have very little experience with them besides my P70 laptop (th-cam.com/video/vRU7U1i2hCU/w-d-xo.html) that contains an ESDI drive.
I have a Compaq Deskpro 386/25 with a Miniscribe 300MB ESDI drive and a WDC based Compaq branded controller. The computer boots and runs but there are corrupted files and I think it's time for some diagnostics. I don't know anything about how that would be done, though. :/ So I second Bandana's keenness for an ESDI video. :)
Brings back memories, also there was some utility that could dynamically test and optimize the interleave - I think you need more than 3 on a slow PC XT ... interleave too low and you end up with 1 sector transferred per revolution, too high - well, interleave neds up being the number of revolutions needed to read the whole track. Interleave 3 means that the track numbering skips 2 sectors and warps around 3 times, so the controller has two sector times to finish transfer and be ready for the next sector
I am another who used to Low level format MFM hard disks with Norton Utils Calibrate to make it run faster by changing the interleave of the disk. No one low level formats hard disks these days but it's equivalent is zero filling hard disks.
Great Video. MFM-RLL has to do with the Harddisk magnetic disk capability. See as Single Density and Double Density. RLL is more dense in magnetic particles. That is what I read about RLL. So only If you have luckily a very good production MFM drive it can in RLL mode, But as you experience in your vid. Lot of bad sectors or hard time to get it formatted and an indication that it will also have hard time to put data on it reliable. An indication is the list of bad sectors on the disk-label, or imperfections of the magnetic layer it is at the start.
That's a neat collection of MFM hdds ! My 286 has a 40MB seagate which is connected to a 16 bit ISA controller. These don't need a bios since the computer's BIOS sets the CHS settings, so I guess that technically this computer could use any of these drives, right ?
Think so ... busy with the exact same setup I think. 16 bit isa mfm controller with 3.5 inch mfm hard drive and an ami bios on the 286. But had to recap the mainboard, desolder all caps from the psu (to find nothing wrong with them), and had to go to dinner just as I got it to boot :) But will keep you posted.
Most Micropolis or Maxtor MFM drives would format out as RLL with no issues. Lots of models of Priam and Rodime would handle it too. Connor and Seagate, forget it. Anyhow, I moved onto ESDI drives because despite their full height I wanted the capacity (at a cost) but I was doing work that paid for such an expense, so no bother.
Conner did not manufacture and drives with this interface, all of their drives were internal controller running as RLL 1,7. I've never met a drive of this era that didn't play nice with my DTC 7287 RLL controller.
No. Many of these drives will start and operate even without platters or heads installed. A board with 2 motors will operate the drives shown, even without the chassis. It could be total junk and still pass it's seek test.
@@RetroSpector78 Mine 5170 is made in spring 85 - it has 512kb ram onboard + 128 on expansion card. Now it has VGA videocard and used with PS/2 series color display. I bought it for 120$ in local used computers store where it was sold for fun - here are some pics of it - at first it was with EGA which I still keep in a box - imgur.com/gallery/li7FQ
@@RetroSpector78 I see Also have working 8 bit Cp/m based machine - Kaypro 10 it runs on 10 mb half height MFM HDD. also have some MFM HDD's in stock - jjust keep them - nothing rare - just items like ST-225 or ST-251-1.
@@yakovkhalip9714 Really nice machine ... Love that design .... Been looking for an EGA monitor for my 5170 for a very long time, and just this weekend I missed out on an IBM 5154 EGA monitor (with an untested IBM 5160) that was sold (combined) for 40 $ !!! Been kicking myself in the teeth since then :)
Very interesting video! Could you do a video on old hard disks with issues? Is there a way to bring them back to life? I have a few old hdd's laying around. Usually when I restore a pc I replace the hdd with an industrial IDE flash drive. But I leave the old disk in to keep it complete. These old disks usually don't work anymore. Either there's a mechanical sound of they are not detected by the BIOS. And I really don't know what to do with these old hdd's. Googling on this topic brings up loads of recovery tools and businesses which can recover your (modern) hdd data. So finding the right search terms is difficult. Do you have any suggestions?
When you here clicking noise you probably can do nothing. First required thing to start the job is clean room, but OK maybe you could build a small filtrated chamber just for your hands and hard drive. The real problem is what you will find inside and this can be a nightmare - like loose/broken head flying around and a lot of scratches on platters. With this you can do literally nothing.
Mediolanon new drives are set to ignore the command.. but... if you want to turn that function on you can through the serial console on the drive.. I don’t recommend it though.
11:55 "a very complex set of instructions" ... that is literally 5 assembly instructions. Even a basic Hello World program takes more instructions than that! I don't see how this can be described as complex?
Great information, way to slow video though. Keep having the same problem with a lot of channels about computers. Unless I really want to learn some stuff beforehand, I'm not intrigued by the video pace.
@@RetroSpector78 I moved over to SCSI really early on with the PC's. Had a 320MB drive back when 49MB was considered a large drive. The 320MB drives was a full height 5 1/4 that would shake a computer case to death. Priam I believe it was.
Thank you for this video ! Thanks to it I found enough courage to try out my own ST-251 with Western Digital controller, which was laying in box for few years, as I had no clue how to approach it. Thanks to the information from your video and actual parameters for ST-251 from the Internet, it took me about 20min from nothing to booting MS-DOS from ancient hard disk :D
It's wild how far computer storage has come since the era of these beasts. My current computer has a 480GB SATA III SSD and it's smaller than even the smallest one of those controller cards, would've been unheard of when these gigantic HDDs were new!
The later 16-bit WD controllers were pretty much exchangeable. I have 3 different WD MFM controller cards and I can use my SD-251 disks with any of them, without the need of LLF.
Thank you so much for this video! This is normally such a murky subject. I have an MFM drive last used circa 1995 and I have been unable so far to properly read the contents to copy them off, after trying 2 different MFM controllers. I can only get a partial directory listing. I think this video plus the heap of various MFM controller cards I happened to pick up lately will enable me to finally read the drive properly. The obstacle, in retrospect of the current retrospect enthusiasm, is that we are used to devices and components being more intelligent, and we don't realize that a few years earlier in industry development, that intelligence didn't exist yet, like IDE drives being able to tell their own geometry to the controller card in in response to a query from the controller card, or actually having a standard mapping for hard drive sectors, like MFM and RLL didn't.
I remember sitting down waiting for drives to format, and later on waiting for them to defrag lol. Things have come a long way in terms of speed, but these were so quick compared to floppy disk's and MS DOS use to load in seconds off an MFM drive.
Try again the adaptec ABC-2072 controller using custom LLF on the so called MFM drive. Whilst giving it a propper step rate (i.e. option #5 which, if I recall corretly, means 70 micro seconds) it will allow the heads to settle a bit and will results in a working LLF. I used this on an ancient Control Data WREN drive which is called MFM type, and it worked fine. In fact, there is no MFM or RLL drives, they just needed to become better in mechanics manufacturing and physics.
Interresting video ,wish i had known all these back then -Nowadys I just despise microsoft for what they did to windows but i guess marketpeople jacked it.
No I don't .... have a zx spectrum / c64 / vic 20 but that's about it .... some older heathkit machines also .... my main focus so far has been x86 machine and will continue to be, but I do like some non x86 stuff every once in a while, and these old 8bit computers also have a special place in my heart.
I have one (MiniScribe Model 3053 assembled in Singapore) & one (model Seagate ST-251 assembled in Singapore) and one large Barracuda that came from my old Dell Computer. Awesome old Computer Harddrives.Also, I have an old (Dec) Digital Celebris GL 6200 with a rebuilt transformer with two large fans in power transformer, and without a harddrive. I have the controller cards. Time to get building now. Thanks ! Awesome video !!
This 8bit ISA era of computing is special, a scene onto itself compared to the later more powerfull dos machines of the mid 1990s. I especially like the Zenith data systems PC clone for their inner architechture. it is also exciting to know tha tnew 8bit ISA cards and CPU boards are being made from scratch once again. one could build an 8bit 8088 pc clone from all new parts, maybe except genuine drives.
Very cool overview! I also have a large collection of MFM/RLL/ESDI drives and almost all types of 8bit or 16bit controllers. makes a lot of fun to use these from time and remember, what you needed to pay that time. haha!
Today there is no real low level format anymore. HDGuru's "Hard Disk Low Level Format Tool" is also not a real LLF. Or? Is there still software that can run a real LLF? With reallocation of sectors.
Now and days, you don't need to low level format the hard drive as the factory it comes from does it before leaving the factory entirely. For example, If you have a Seagate Barracuda, it's already low level formatted before leaving Seagate's factory. I do remember the ST351A had a sticker that said CAUTION: DO NOT LOW LEVEL FORMAT. I assume that type of drive was the first that came as pre low level formatted. Update: I did the research and the ST351A/X was the last stepper motor drive made by Seagate before switching to voice coil drives
I had a WD1002 with a fixed BIOS in a Commodore PC-10. Some kind soul had actually dumped the SuperBIOS ROM on the web several years ago... I was able to burn it to an EPROM and use the card again with an ST225 when the original Microscience 10MB drive died.
Yeah can imagine this being a pain back in the day .... luckily I was able to score a bunch of 8 bit cards a while back that included a lot of mfm controllers.
I once had a computer with an 80 MB drive. The odd thing was I could only get 60 out of it. I am not sure what was happening. Maybe it was a loss from formatting? A controller for a similar drive of lower capacity than what I had? I always thought it was weird.
@@zoomosis I don't know what it was but I was able to use the drive. I set the BIOS according to the parameters on the label anyhow. I don't use that computer any more anyhow. That was just an old one I used to write out my homework and stuff.
Not exactly true A harddrive low level formatted on an older tech controller will work fine on a newer card without reformatting. Or at least it should. You can take a pcAT mfm and stick it on a VLB mfm ( the very last generations of mfm) controller and read and write just fine.
Might be a difference between xt / at ? I think each vendor (seagate, western digital...) have their own way of doing the low level format routines on the hard drives. And as the bios for these XT mfm controllers is included on the card itself (and not the computer), it is the card that needs to be able to interpret the hard drive encoding.
@@RetroSpector78 yes 8 bit couldnt read 16bit mfm format. And yes the card manufacturers had different commands and proceedures for initiating the low level format. But once it was done it was portable. For example You could take a 16bit-formatted st225 from a seagate controller and drop it into a machine with a 16bit WD controller. But. There were limitations. Some older controllers couldnt keep up with faster interleaves so if it was formatted 1:1 on a fast card you couldn't go backwards to a card that maxed at 3:1 interleve And 16 bit mfm cards werr supposed to be able to read 8bit formatted drives. But it didnt always work. Sometimes you had to move the controller too.
You did all that for 90 MBs of storage? Why that's just stupid the hatd drives belong in the trash. A micro sd has more storage. Hell a zip drive has more room.
What a stupid comment. The point isn't for storage, its the history and showing how these things work with the equipment of that era. Like no one knows they are small drives... Christ.
Thanks for the refresher on this stuff. I used to do all of this back in the 80s and had forgotten a good bit of it, but as soon as you mentioned "debug", I then remembered "-g=c800:5". Good times!
As a kid I collected hard drives and loved low level formatting them & mapping bad sectors. I was a weird 10 year old.
When I was 10 I copied what seemed like 100 pages of BASIC code from a philips msx manual into the computer, resulting in a launchpad popping up on the screen, launching a rocket into space. We all had various degrees of weirdness back in the day (and even still today according to my wife)
@@RetroSpector78 I'm just glad I found where I fit in :)
My kind of club. I remember taking a family road trip around 6th grade, kept myself occupied with a thick Serial Communications book and the user manuals to OS/2. My mom still talks about how my grandmother would look back at me with a confused expression and ask, "what is he reading..?" 😄 The only thing I regret is that there wasn't more detail about how the Zmodem protocol worked under the hood. hehe
as a kid hard drives were my passion too...great pleasure when i could llf and recover a dead drive..then i ran all kinds of disk utilities on it, msdos scandisk, norton 4.something and others i cannot remember anymore. apart from the old mfm and rll's, old WD caviar series were my favorite IDE drives both the silver ones but especially the black ones up to 500mb they were bulletproof
@@MrHBSoftware Something about resurrecting an old drive is just so satisfying. Plus I loved all the different sounds each brand made!
This is pure gold, thanks for giving us much detailed information, there’s a lot of confusion on these topics.
Wonderful video you've really gone through this nicely. I have six MFM's and three RLL's here at home in use in my collection. Really enjoyed this as I've gone through this journey more than a few times over the decades. :)
I learned this the hard way when i whas young and selling xt class machines. I had a teacher who whas in charge of the informatica systems of that particular school, and he had a room full of xt class machines that wher decommisioned, and since i had a great friendship with this teacher, he told me that those machines needed to be thrown out some day, so i asked if i could sell em, we ended up asking the prinicipal and he said sure, i could keep 1/3th of the selling price per pc, so i got to work, and they all used this kind of hard drive! Its insane how long it took me to figger out how to properly set them up, i ended up selling over 200 pc's for about 5000 belgium francs each (it whas a long time ago), so i made a good amount of money from those machines, i spend HOURES low level formatting xt machines! Insane how long 1 pc could take to format a hdd! How bigger the drive, the longer it takes! I had sometimes 6 pc's in my room all low level formatting at the same time :p insane how the times have changed man! Great video! Love this stuff!
My memory back in the day was that we were so happy when an mfm drive would reformat on rll. i ran a seagate 20 meg mfm disk on rll for five years with no issues. I remember lots of drives didnt work and lots did. My seagate was a half height model from about 1987.
That's right .... I once did it by accident, hooking up an MFM drive on a RLL controller and was so confused why my 20MB drive had 30MB after formatting.
I totally forgot how I used to do this. Thanks for the refresher. It's only been thirty years? Dang! SATA is a blessing. I see your monitor is as dirty as my test monitors. Great video.
It's always reassuring to see someone doing this with confidence! :-)
30KB bad sectors when getting 20MB out of 10MB MFM drive seems like a great deal
This one was a special case, it was the 20mb basf drive being formatted by an RLL controller that was configured to use 17 sectors / track. So you end up with the same capacity as you would with MFM. Some RLL controllers allow you to set it like that for compatibility reasons. But the bad sectors were the result of the RLL encoding. If it was setup to use 26 sectors it would have formatted to 30MB.
Gonna do something more in-depth on RLL but still waiting on some hardware to make the video.
I have a Type 1 just like here, with 0 bad sectors. I was blown away when I formatted a near 40 year old hard disk and it came up perfect. I promptly installed DOS 6.22 and Windows 3.0. I think I have 1.5 Mb free ;)
Rll encoding was possible on almost all mfm drives. The key to doing it relies on head position accuracy. Some drives were more accurate than others. This gave a lot of rll formatted drives the reputation of being not reliable.. eventually this wasn’t a issue. But the damage was done. The conner drives were great with rll. The rll format gave a good performance increase. A lot of 30mb drives were rll formatted 20mb mfm drives.
As from my experience, and as I comented a minute before, the adaptec ACB-2072 only needs to be used with custom settinfs and a longer step rate to let the heads and mechanics settle. I'm using 70 micro seconds on and very old, so called MFM drive with no issues.
Bad sectors on these drives are common from the factory.
What you do have to watch out for buying second hand are lots of additional hand scribbled bad sectors, one or two is fine, but I've seen drives with multiple post it notes full of bad sectors listed.
Cool. Learned a bunch. I have a number of mfm drives that need attention. Did not know these specifics. They probably won't work anyway but I can test them better anyways.
Cool ! Great ... if you have any other questions just drop a comment here.... happy to help
Can't wait for the video on ESDI drives.
You know something I don't ? :) Have very little experience with them besides my P70 laptop (th-cam.com/video/vRU7U1i2hCU/w-d-xo.html) that contains an ESDI drive.
I have a Compaq Deskpro 386/25 with a Miniscribe 300MB ESDI drive and a WDC based Compaq branded controller. The computer boots and runs but there are corrupted files and I think it's time for some diagnostics. I don't know anything about how that would be done, though. :/ So I second Bandana's keenness for an ESDI video. :)
Brings back memories, also there was some utility that could dynamically test and optimize the interleave - I think you need more than 3 on a slow PC XT ... interleave too low and you end up with 1 sector transferred per revolution, too high - well, interleave neds up being the number of revolutions needed to read the whole track.
Interleave 3 means that the track numbering skips 2 sectors and warps around 3 times, so the controller has two sector times to finish transfer and be ready for the next sector
Man, you refresh my memories, now I remember testing for optimal interleave in my first XT machine! It's strange to remember such things...
I am another who used to Low level format MFM hard disks with Norton Utils Calibrate to make it run faster by changing the interleave of the disk. No one low level formats hard disks these days but it's equivalent is zero filling hard disks.
How did I kmow about MFM in 1995? The era of IDE. I was just playing with CD's back then.
Great Video. MFM-RLL has to do with the Harddisk magnetic disk capability. See as Single Density and Double Density. RLL is more dense in magnetic particles. That is what I read about RLL.
So only If you have luckily a very good production MFM drive it can in RLL mode, But as you experience in your vid. Lot of bad sectors or hard time to get it formatted and an indication that it will also have hard time to put data on it reliable. An indication is the list of bad sectors on the disk-label, or imperfections of the magnetic layer it is at the start.
That's a neat collection of MFM hdds !
My 286 has a 40MB seagate which is connected to a 16 bit ISA controller. These don't need a bios since the computer's BIOS sets the CHS settings, so I guess that technically this computer could use any of these drives, right ?
Think so ... busy with the exact same setup I think. 16 bit isa mfm controller with 3.5 inch mfm hard drive and an ami bios on the 286. But had to recap the mainboard, desolder all caps from the psu (to find nothing wrong with them), and had to go to dinner just as I got it to boot :) But will keep you posted.
@@RetroSpector78 I believe, these early 8-bit MFM controllers used to store some configuration date on the drive itself...
Where can I get that software for my XT clone ?
Most Micropolis or Maxtor MFM drives would format out as RLL with no issues. Lots of models of Priam and Rodime would handle it too. Connor and Seagate, forget it. Anyhow, I moved onto ESDI drives because despite their full height I wanted the capacity (at a cost) but I was doing work that paid for such an expense, so no bother.
Conner did not manufacture and drives with this interface, all of their drives were internal controller running as RLL 1,7. I've never met a drive of this era that didn't play nice with my DTC 7287 RLL controller.
I actually have a copy of the book hard drive bible that covers a lot of the rll, mfm, ide, and early sata! Dam thing is about 2.5” thick loaf
Love these old drives. And also surprised by their failure rate. More than half of the ones I come accross still work.
I have the last published edition of the Hard Drive Bible, eighth edition which was published in the mid 90s, before SATA was invented.
Sir, can I test this type old Hard-Disk by just connecting the power plug?
No. Many of these drives will start and operate even without platters or heads installed. A board with 2 motors will operate the drives shown, even without the chassis. It could be total junk and still pass it's seek test.
Ah! That explains quite a few things
Interesting retrospective, watching this on a system with 18 TB of storage.
That’s cheating ... in what year are you watching this ? :)
Nice video ! I have an IBM 5170 with 20mb double height MFM seagate - still works!
Yep... also have lots of mfm drives that are still running fine. Seems the very early full height IDE ones are a lot more sensitive to failures.
And the IBM 5170 is one of the greatest machines to have ... what kind of monitor have you got hooked up to it ? IBM one ?
@@RetroSpector78 Mine 5170 is made in spring 85 - it has 512kb ram onboard + 128 on expansion card. Now it has VGA videocard and used with PS/2 series color display. I bought it for 120$ in local used computers store where it was sold for fun - here are some pics of it - at first it was with EGA which I still keep in a box - imgur.com/gallery/li7FQ
@@RetroSpector78 I see Also have working 8 bit Cp/m based machine - Kaypro 10 it runs on 10 mb half height MFM HDD. also have some MFM HDD's in stock - jjust keep them - nothing rare - just items like ST-225 or ST-251-1.
@@yakovkhalip9714 Really nice machine ... Love that design .... Been looking for an EGA monitor for my 5170 for a very long time, and just this weekend I missed out on an IBM 5154 EGA monitor (with an untested IBM 5160) that was sold (combined) for 40 $ !!! Been kicking myself in the teeth since then :)
Very interesting video! Could you do a video on old hard disks with issues? Is there a way to bring them back to life?
I have a few old hdd's laying around. Usually when I restore a pc I replace the hdd with an industrial IDE flash drive. But I leave the old disk in to keep it complete. These old disks usually don't work anymore. Either there's a mechanical sound of they are not detected by the BIOS. And I really don't know what to do with these old hdd's. Googling on this topic brings up loads of recovery tools and businesses which can recover your (modern) hdd data. So finding the right search terms is difficult.
Do you have any suggestions?
When you here clicking noise you probably can do nothing. First required thing to start the job is clean room, but OK maybe you could build a small filtrated chamber just for your hands and hard drive. The real problem is what you will find inside and this can be a nightmare - like loose/broken head flying around and a lot of scratches on platters. With this you can do literally nothing.
What happend go c800:5000 adres to init low level format routine?
Ah, ok its at 15 minutes and apparently my memory is also corrupted.
Mediolanon new drives are set to ignore the command.. but... if you want to turn that function on you can through the serial console on the drive.. I don’t recommend it though.
Commodore 64s I believe had either MFM or RLL floppy drives. A PC floppy drive can not read those (I tried).
IIRC Commodore disk are GCR encoded
low tech rocks!
11:55 "a very complex set of instructions" ... that is literally 5 assembly instructions. Even a basic Hello World program takes more instructions than that! I don't see how this can be described as complex?
Now you can find a micro SD memory of 500Gb
Great information, way to slow video though. Keep having the same problem with a lot of channels about computers. Unless I really want to learn some stuff beforehand, I'm not intrigued by the video pace.
Thx for the feedback .... will keep it in mind ... youtube does have a playback speed control ... don't know if that helps ?
I remember learning the hard way with MRM drives. I use to have 50 of them in a closet waiting to be used. Mom trashed them when I moved out.
Bitch. I bet you were very angry.
Learned the *HARD* way :p
Should've taken them with you, then
Those would be worth much in today's retro rebuild market.
I always formatted my MFM drives with RLL controllers. More space and better speed. Pretty much never used MFM once RLL was available.
I have a shortage of RLL controllers to do that :)
@@RetroSpector78 I moved over to SCSI really early on with the PC's. Had a 320MB drive back when 49MB was considered a large drive. The 320MB drives was a full height 5 1/4 that would shake a computer case to death. Priam I believe it was.
Thank you for this video ! Thanks to it I found enough courage to try out my own ST-251 with Western Digital controller, which was laying in box for few years, as I had no clue how to approach it. Thanks to the information from your video and actual parameters for ST-251 from the Internet, it took me about 20min from nothing to booting MS-DOS from ancient hard disk :D
That's really great ... gla the video helped ! Enjoy your 42MB of free disk space ! :)
It's wild how far computer storage has come since the era of these beasts. My current computer has a 480GB SATA III SSD and it's smaller than even the smallest one of those controller cards, would've been unheard of when these gigantic HDDs were new!
Sorey exactly ... just think about a mini sd card containing 128 GB vs a full height 5.25inch mfm hard drive with a capacity of 10 MB.
what an amazing walk through - thanks a lot! this is very helpful, and it includes all the details one might need! This is very thoughtful! thanks!
The later 16-bit WD controllers were pretty much exchangeable. I have 3 different WD MFM controller cards and I can use my SD-251 disks with any of them, without the need of LLF.
Thank you very much for this very informative video!
How do you know which controller is MFM and which is RLL? I want to buy such controller but i cant find info about it if its MFM or RLL.
Check the documentation for your controller. MFM encoding controllers will operate RLL drives without issue.
Thank you so much for this video! This is normally such a murky subject. I have an MFM drive last used circa 1995 and I have been unable so far to properly read the contents to copy them off, after trying 2 different MFM controllers. I can only get a partial directory listing. I think this video plus the heap of various MFM controller cards I happened to pick up lately will enable me to finally read the drive properly. The obstacle, in retrospect of the current retrospect enthusiasm, is that we are used to devices and components being more intelligent, and we don't realize that a few years earlier in industry development, that intelligence didn't exist yet, like IDE drives being able to tell their own geometry to the controller card in in response to a query from the controller card, or actually having a standard mapping for hard drive sectors, like MFM and RLL didn't.
is amazing. congratulations!!.
I remember sitting down waiting for drives to format, and later on waiting for them to defrag lol.
Things have come a long way in terms of speed, but these were so quick compared to floppy disk's and MS DOS use to load in seconds off an MFM drive.
"Complex set of commands" that's one term to describe hand writing 16-bit x86 assembly in a REPL...that's actually wild.
Wish I could find a BASF drive like that, they're very uncommon in the USA.
imagine 3.5'' ssd and 5.25'' ssd the bigger one would be around 40tb
1sonyzz And around $12,000 and slower than a smaller drive
When you're out of touch: 20:12 asks for y/n types in Yes.
Impressive to see you made it that far in the video and still managed to spot that :) hope you enjoyed the video.
@@RetroSpector78 I always enjoy your videos. Thanks.
Thx a lot appreciate it !
If you're ever interested in selling that BASF mech for any price, send me an email!
Try again the adaptec ABC-2072 controller using custom LLF on the so called MFM drive. Whilst giving it a propper step rate (i.e. option #5 which, if I recall corretly, means 70 micro seconds) it will allow the heads to settle a bit and will results in a working LLF. I used this on an ancient Control Data WREN drive which is called MFM type, and it worked fine. In fact, there is no MFM or RLL drives, they just needed to become better in mechanics manufacturing and physics.
Hi
Thanks for sharing. Excellent guide.
I was able to revive my St225 hard drive with Wd1002a controller on old Juko Xt computer.
Regards.
Interresting video ,wish i had known all these back then -Nowadys I just despise microsoft for what they did to windows but i guess marketpeople jacked it.
I just got my first MFM drive from the dumpster, so I will use this to Low level format them.
12:27 thats what she said... sorry
Another way to low level format and set the interleaving was to use the Norton Utilities Calibrate program.
Z80!!! Legendary microprocessor!!!
dee
interesting! It drove me back in the days... :)
Great to see how most of them still work. I only started getting into pc’s in the 486 era. Even that seems like a long long time ago.
Great to see all the old hardware again
Great days
Do you have a bbc torch in your collection ???
No I don't .... have a zx spectrum / c64 / vic 20 but that's about it .... some older heathkit machines also .... my main focus so far has been x86 machine and will continue to be, but I do like some non x86 stuff every once in a while, and these old 8bit computers also have a special place in my heart.
Thanks to this video i finally installed my old Kalok Octagon, you got a new sub
Nice! Love a good Kalok, I've got their entire product lineup.
I have one (MiniScribe Model 3053 assembled in Singapore) & one (model Seagate ST-251 assembled in Singapore) and one large Barracuda that came from my old Dell Computer. Awesome old Computer Harddrives.Also, I have an old (Dec) Digital Celebris GL 6200 with a rebuilt transformer with two large fans in power transformer, and without a harddrive. I have the controller cards. Time to get building now. Thanks ! Awesome video !!
This 8bit ISA era of computing is special, a scene onto itself compared to the later more powerfull dos machines of the mid 1990s. I especially like the Zenith data systems PC clone for their inner architechture. it is also exciting to know tha tnew 8bit ISA cards and CPU boards are being made from scratch once again. one could build an 8bit 8088 pc clone from all new parts, maybe except genuine drives.
Very cool overview! I also have a large collection of MFM/RLL/ESDI drives and almost all types of 8bit or 16bit controllers. makes a lot of fun to use these from time and remember, what you needed to pay that time. haha!
Today there is no real low level format anymore.
HDGuru's "Hard Disk Low Level Format Tool" is also not a real LLF. Or?
Is there still software that can run a real LLF?
With reallocation of sectors.
Yeah, if you do LLF on new HDD it will:
1. Not let you
2. If it let you do that, say bye to your HDD
Now and days, you don't need to low level format the hard drive as the factory it comes from does it before leaving the factory entirely. For example, If you have a Seagate Barracuda, it's already low level formatted before leaving Seagate's factory. I do remember the ST351A had a sticker that said CAUTION: DO NOT LOW LEVEL FORMAT. I assume that type of drive was the first that came as pre low level formatted.
Update: I did the research and the ST351A/X was the last stepper motor drive made by Seagate before switching to voice coil drives
I've owned most of the drives at one point.
I fornat low level to many HDs, good results! SINCE 1985
Yeah amazing how some of them have proven to be much more reliable than ever thought.
@@RetroSpector78 I LOVE THIS CHANNEL !
Coleção Nintendo thx a lot, glad you liked it !
Coleção Nintendo thx a lot, glad you liked it !
@ 0:23 - ST-412 MFM - now i am curious
i think i also have the Xebec 8bit - but - a different model
cannot post pictures here :/
@@herauthon IBM shipped the Xebec controller in XTs for many years
I had a WD1002 with a fixed BIOS in a Commodore PC-10. Some kind soul had actually dumped the SuperBIOS ROM on the web several years ago... I was able to burn it to an EPROM and use the card again with an ST225 when the original Microscience 10MB drive died.
Yeah can imagine this being a pain back in the day .... luckily I was able to score a bunch of 8 bit cards a while back that included a lot of mfm controllers.
What camera are you using? :O
Iphone X :)
I once had a computer with an 80 MB drive. The odd thing was I could only get 60 out of it. I am not sure what was happening. Maybe it was a loss from formatting? A controller for a similar drive of lower capacity than what I had? I always thought it was weird.
Wrong drive type set in the BIOS? Or were you getting 20 MB of bad sectors?
@@zoomosis I don't know what it was but I was able to use the drive. I set the BIOS according to the parameters on the label anyhow. I don't use that computer any more anyhow. That was just an old one I used to write out my homework and stuff.
Not exactly true
A harddrive low level formatted on an older tech controller will work fine on a newer card without reformatting. Or at least it should.
You can take a pcAT mfm and stick it on a VLB mfm ( the very last generations of mfm) controller and read and write just fine.
Might be a difference between xt / at ? I think each vendor (seagate, western digital...) have their own way of doing the low level format routines on the hard drives. And as the bios for these XT mfm controllers is included on the card itself (and not the computer), it is the card that needs to be able to interpret the hard drive encoding.
@@RetroSpector78 yes 8 bit couldnt read 16bit mfm format. And yes the card manufacturers had different commands and proceedures for initiating the low level format. But once it was done it was portable. For example You could take a 16bit-formatted st225 from a seagate controller and drop it into a machine with a 16bit WD controller. But. There were limitations. Some older controllers couldnt keep up with faster interleaves so if it was formatted 1:1 on a fast card you couldn't go backwards to a card that maxed at 3:1 interleve
And 16 bit mfm cards werr supposed to be able to read 8bit formatted drives. But it didnt always work. Sometimes you had to move the controller too.
11:50 you are programming in assembler mate! those are not "commands"
New sub here ;)
Welcome ! Hope you enjoy the show. Be sure to checkout the other content and like / share / leave a comment ! Thx a lot.
Time for somebody to create the mother of all hard disk controller cards.
You did all that for 90 MBs of storage? Why that's just stupid the hatd drives belong in the trash. A micro sd has more storage. Hell a zip drive has more room.
20mb to be exact :)
What a stupid comment. The point isn't for storage, its the history and showing how these things work with the equipment of that era.
Like no one knows they are small drives... Christ.
Thanks for the refresher on this stuff. I used to do all of this back in the 80s and had forgotten a good bit of it, but as soon as you mentioned "debug", I then remembered "-g=c800:5". Good times!