Why are Floppy Cables Twisted? [Byte Size] | Nostalgia Nerd
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- เผยแพร่เมื่อ 2 ต.ค. 2024
- It's the age old question. Why, oh why, is there a twist in the floppy disk drive ribbon cable? Ever since I opened up my first PC I've looked that that twist and thought... that seems out of place. But the reason behind it is actually based in pure common sense, and maybe an over engineered original solution, perhaps. We look at the floppy drive twisted cable, along with the cable select protocol of IDE cables.
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Praised be SATA, who liberated all the slave drives.
Now we are all masters!!
Jack Kraken
you cant be master without a slave
You can be a master of your own destiny.
Abraham Lincoln likes this element.
let my people go, man!
1985: My first PC
2019: So THAT'S how Cable Select works!
Dropped down the comment section to say the same damn thing. During my youth I was under the impression CS would just magically let the drive I want be set to master. Had no clue how it actually worked until now. Haha.
@@Donchikiman Agree.. I thought it was triggering some actual negotiation between the drives, but this does explain why sometimes it wouldn't work (using a cable without the cut!) I also remember taking apart some cables, and finding the cut (missing pin) only within the connector at the end, so that was confusing..
Same here in 2020!
I remember those days... and ribbon cables are one thing I don't miss about them. "Cable management" and "airflow" were a bit different then...
Round cables.
@@HappyBeezerStudios Indeed. Made life just that little bit easier.
@@HappyBeezerStudios Or DIY square cables by carefully segmenting and stacking. ;)
Cable management? What cable management?
back then no one cared about air flow back then it was all about the it was all about radiation shielding
This video makes me feel every bit of my 38 years.
User He probably still has some 50 years left.
@@mygaffer Relatively speaking, we all are. And if you think you're going to leave an impression, try recalling the name of each of your great grandparents.
@@KurtRichterCISSP my only hope is to write a tesis thats good enough so that people every 40 50 years jump on it and say, hey that adriazola guy was smart.
@@ivanadriazola1991 Just make sure you have an editor for spelling and grammar. Lol
Simply Sherbert oh... No worries... I’m 13 and i own my own usb floppy disk and floppy drive... Actually store some stuff on em’... (￣▽￣ v)
Kids could watch this and not know the perils of the slaves and masters.
Back in the day when I asked myself this same question, I simply read the pin-out spec (didn't everybody?), and my curiosity was sated, but you did go a bit deeper here. Good job.
By the time I was getting into PCs, the dual floppy setup was extremely rare. Though I did get my hands on a second one at one point and set it up to copy shareware floppies.
copy "shareware" floppies, oh of course, say no more sir
I see we are becoming quite the merry thread of people who know the fun and joy of using a belt punch tool on specific sectors on floppies.
Eurotrash RC
look up
"don't copy that floppy" on youtube
I'm pretty sure I did, too. But it's been a long time, and I had forgotten. And videos tend to contain more information than just answering the question.
I didn't know they eventually removed the B: (/dev/fd1) drive from some cables, for example. Nor did I ever think to ask how cable select on IDE drives worked.
Were these twists added by hand? I'd imagine it would be quite complicated to get a machine to do it.
Larry Bundy Jr, nice seeing you here!!!!
"top 10 hardware hacks added to consoles by by hand"
You sir are everywhere lol. STOP STALKING ME!!!!!!!!!!!!!!!!!!! Love ya Larry
many computer components and other electronics are assembled by hand.
Not at all hard to add it with a machine. Imagine a wire feed guide being a round block with a slot for the wire the go through. To twist the wire instead of just pushing it straight down the wire, you thread the outside and push it through a threaded tube so that it wants to screw into the tube and thus spins in a circle.
Haha so many things i knew and are placed on a backup medium in my head, as i haven't used this in ages. Floppy drive / ide selection jumpers. Ow the fiddling on those, without taking out the drive (lazy). Darn if you dropped those jumpers somewhere in the case, holding shaking the case to get the jumper out, must have happened once to everyone.
There are still jumpers on modern boards. and luckily basically almost every other connector uses the same 1/10 '' pitch, be it front heads, USB or fans.
If the jumpers are too small there are some with a little flag on that helps getting them out.
I was never able to get 2 IDE drives to function with 'cable select', and thanks to this video, I now know why. I had no idea that the cable needed to have a wire cut.
Wish I had seen this a decade ago!
me too, now that I know. I think we took the right decision of using the jumpers, it was easy enough to use the master and slave jumpers.
I had a cable with that cut only once. Only one cable in 34 years. That's how rare those were.
Now the question is, does it matter which drive you set for master when you configure yourself?
+Snetmot Nosrorb Windows would not boot from a slave drive if I remember correct.
+DecibelAlex Probably right. But I was thinking more in terms of performance.
What a twist!
th-cam.com/video/ag1vabERNn0/w-d-xo.html
@@lightsup55 "Video is private"
Thanks for clearing up the reasons behind the twist, I didn't know that was it. Also the gap in the IDE cables one was a mystery for me - I genuinely thought my IDE cable was damaged when i noticed that. I guess i can now safely put it into service note that I know. Still, setting jumpers on the drives is not so bad that I would be complaining about no autoselect capabilities.
I think what I like about a lot of these videos is that they answer questions I had about PC building in the pre-internet age, and which I never thought to look up since getting easy access to the answers.
Thanks againfor answering the questions I forgot I had!
Nostalgia nerd I don't want to put you under pressure but when will you do a game boy video? Because you have been talking about doing it for quite a while .
I didn't know i needed to know this, but now that I know it im totally intrigued.
I hate the IDE cable with such passion, its unbearable
One less thing to dream about. I still dont understand why they stopped using the Ready signal tho. I must admit it was indeed a pain building a pc back then having to set IRQ's & DMA's manually with jumpers and make sure they didnt conflict. However being able to set & configure the drives yourself was easy and not a chore and it has only made it harder with time to make em backwards compatible. Something that most retro games has probably figured out by now.
I miss IDE cables, I never had to replace one. On the other hand some SATA cables that I bought in 2012, I had to replace them recently. But it is hard to tell a good quality one from a cheap one just from eyesight.
I remember as child I always imagined that mysterious thing called PC must look awesome on the inside -- probably inspired by some SciFi movies. When then I had the first chance of being alone with an old model and a screwdriver I finally looked into one... and was hugely disappointed what a chaotic mess the thing is on the inside... the twist on the cable being only a minor flow as in why is this thing full of cables running amok anyway.
2019: these hacks are still standard procedures in many environments.
O damn... these jumpers! I really hated them. Ironicly my new motherboard has alot of jumpers to switch some important features on or off.
i personally would prefer dip-switches over jumpers.
Wish i had known this 20 years ago :|
Your drives are upside down! Would still work I guess...
Tristan Buckley I noticed that on the images too. It was bugging me :-)
All the bits fell out!!
+Lasse Huhtala You get a B for effort... (Was an A but the cable was twisted!!)
Just noticed it after reading your comment, but I remember that there just was something that was bugging me while seeing it initially :D
I’m willing to bet a million pounds that when they first designed the floppy drive, they accidentally built it the wrong way round and had to twist the cable to make it work. The amount of times where I’ve built something the wrong way round in games and had to do a twist to compensate is in the hundreds, so I wouldn’t be surprised if this really happened.
Floppies were still used in the early 2000's for dealing with school work. Better networks and USB thumb drives made them irrelevant.
I always wondered about that. Thanks to you, now I know.
So.. here's the question... If they set up all the drives to be "B", and needed a twist to make them "A"... then why not make them all "A" and needed the twist to make them "B", since more than likely back-in-the-day people were cheap and may not have been able to pay for an extra floppy? (And thus would have probably liked/could have had a cable without a twist at all?
Jonathan Herr Back in the day, people had no harddrive, but two floppy drives. Harddrives were very expensive in the eighties.
Suhkma Dheek that makes a bit more sense. a drive in the middle would be unintuitive and an a only cable whilst simpler, would be redundant/useless if you needed two drives. (you'd have to buy an additional cable)
The pinout on the actual drives and the connectors was decided before the whole twist thing became a thing. It's a workaround to a legacy thing.
OMG I remember how much shit had to deal with using ide cables. Or realizing I don't have a ide cable for a hdd
I wish I knew this 15 years ago, when I was still using IDE cables.
For those of us who still fiddle with ide cables, thanks! :)
Some old motherboards had the "Swap floppy drives" option in the Bios.
I used to just cut the floppy cable after the first plug, then use that option so drive B: is seen as A:
I always enjoy your videos. Keep up the good work!
Many thanks sir!
I had a Multi-IO card that expressed it so clearly in the manual: "Use flag distance cable please check pin 1 make correct to connect disk port golden pin. Cable other hand have two 34 pin female disk connector distance cable longer connector is DRIVER A." [sic.]
That sounds like a present day Facebook comment.
And now we get something of that old-time magic with Chinese products with their instructions put through Google Translate.
I love Chinglish.
I still have an odd sony singlespeed atapi cdrom drive hooked up to an isa atapi adapter in my 80286 retro system.
Is retro nerd a language in google translate these days??? :P
Synthusiast Gnarly dude
Do you run it off the board, of a controlelr card or off the soundcard?
AT keyboard? Or one of those new fangled ATX sockets?
If only there was youbook in the 90's, when this would be helpful to know. :)
That's not an A drive, that's an AWESOME drive!!..
So, now we have to solve the mystery why the manufacturers never used the notches on the 3,5" floppy connectors correctly. :-/
I have got several drives which have notches on both sides of the connector. And motherboards which have none.
Your first try in connecting them will always be wrong!
I wondered about this too. And we still need floppies to update our motherboard firmware.
I've wondered about this for 17 years and never thought to google it. Thank you!
Wow, this is relevant. I just bought one on ebay the other day realizing that all I had was IDE cables.
I had a cable that was missing pin 3 (as is the floppy drive), but the motherboard had all the pins. Do you know why that is?
kirbyswarp well one of the voltage or ground pins wasn't necessary in later designs and thus the cable was probably just not necessary for function at the time saving a few thousand dollars for the company
Well, I hope it works because I don't have another floppy drive. And I kind of need to flash the bios.
Depending on how new the board is you could flash from usb.
Or start up a DOS from CD to do the flash. Atleast that is what I did when I had no functioning floppy drive.
It's a pentium 3. No USB port on the motherboard, as far as I could tell floppy is the only way.
If you used the 80-wire ATA66+ cables, cable select worked, with the slave usually being in the middle. I standardised on this for many years. As for floppy cables, I used to make my own sometimes to neaten up people's systems... I've had to do a few with two twists. On my first PC, the internal floppy drive had to be set as DS0, and I found a few on which that could not be done, or didn't work. Fortunately the two never coincided, but I could have modified the cable if necessary.
Actually have two froppy drives around that differ, one has the jumper puins the other misses them, but then they are in different ssystems anyway.
80-wire IDE cables were the best, they reduced cross-talk and interference. They were basically a *must* if you were going to be burning DVD's on PATA.
Sadly most people hadn't a clue that some PATA cables had 80 wires while others had 40. I walked into my local PC supply store and asked the guy for an 80-wire ATA cable and he looked at me like I had four heads. He then looked around and found a box of loose wires and said "is it one of these"? I was like "OMG" Dude wasn't even one of those guys from Best Buy or some other box store, but a local PC store for enthusiasts.
When I worked IT I'd hoard them as we scrapped older units for spares. Probably pitched a few dozen 40-wires, but I held onto those 80's, they were surprisingly hard to come by.
Ahh I forgot about this but in my defence it's been along time since I've used one, hmmm not since a entire 3.5" would fit your entire ASM(Assembler) course work. God I feel old :)
i waiting for this answer about 20 years :D
So the master ide goes in the middle... 20 years wasted, God damn.
Listening to the whole vid it sort of depends, and I have had systems I built wiith 4 floppies for data transfer, and 1.44MB drives, 5.25in ones with 3.5in as well, getting the right cable to talke to the motherboard. And answering why drives had to be B with setting the A rather than the other way round was that software programmes generally were set to look for A so if a system had two As they would clash- in the BIos as well, two Bs would just be ignored generally and no harm done as only one could be made an A
They are "twisted" because they are AWESOME! of course. End video now.
4:40 the corrosion on that board is real real ugly. :(((
They're twisted cause they're crazy!
The Floppy standard was overly complicated from day one. A simple non serial system could have used between 6 and 8 wires and each drive should have had its own motherboard connector that could have been used for internal or external drives. A binary mode controlled system could have been done with as little as 3 wires, but 4 would have been better.
I think you just invented the USB
oh yeah.... never took note before - thanx, you've made me realize I'm not as nerdy as I thought - unless it comes to 70's-00 cars.... yup then I really have no get out of jail free card like this.
I've repaired 100's of computers and I always just thought this was because of manufacturer error.
I saw cable select, and ribbons with that missing part, but never know why. I guess I got lucky plugging things in the right way :)
I unplugged a floppy cable once and it corrupted my screen on boot up even tho I didn't need it to boot windows anymore. Was perfectly fine after plugging the floppy back in
Voodoo 2 sli cable is also twisted :|
Alright, with the mystery of the floppy cable twist revealed, now move on to SATA cables..... as in, why do SATA cables only have ONE connector instead of multiple ones like IDE (PATA?) cables had? The answer is probably revealed in the terminology, Serial or Parallel - either way, GO!
What is that map of in the poster seen at 0:44?
That was an Unexpected Plot Twist. *drum roll* 😀
Tough crowd... i know LOL ☺
Seriously instead of A: B: it should be Slave Master like HDs
but hey maybe MSDOS was a mess beyond repair
or maybe IBM was so arrogant they couldn't care less
who knows really why They took that /Path/ *drum roll* 😀
Thanx for reading ☺
It should be Drive 1 and Drive 2, as Shugart specified.
And Drive 3 and Drive 4 as well, since the Shugart Interface defined FOUR drive select lines, not two.
IBM closed off the four-drive possibility by adopting the twisted cable instead of setting DIP switches or jumper blocks PROPERLY. And made life harder for everyone that owned a computer with a properly-configured disk controller down the line, as they started shipping drives with no switches or jumpers that could ONLY be used the IBM way.
(I grudgingly admit that it makes the assembly line run smoother if all your disk drives are configured the same way, since no one can accidentally install a Drive 2 into a single-drive system, or two Drive 1s into a dual-drive machine)
As a side note when you had 2 drives connected without the twist or had the jumpers set the same strange things happened. The computer would try to use both drives at the same time and mostly would lead to errors but sometimes rarely you could get a setup where it would write to 2 disks at the same time.
Also, Early Jumpers weren't little plastic thing that covered some pins that moved easily (and got lost easily). The floppies on my Kaypro machines (z80 cp/m machines circa mid 1980's) have what an small dip socket but instead of a chip it would have a piece of plastic with legs and with pieces of metal going across. To open the jumper you pry up on the metal pieces so they don't connect. To Close the jumper you push the pieces of metal back down... With those kinds of jumpers the wire swap is nice.... Also, a Question.. What about the 7 wire twist on MFM and RLL hard drives? was it the same thing?
The specification for drives originally supported 4 drives. If you look at really old 5.25" drives they have 4 drive select jumpers. Some old Tandy computers (the non-PC based ones) could run 4 drives.
I miss floppies, what I liked most about them was that you could stick them in a box and flick through them like cards. They were a really tangible chunk of storage that was easy to manage and organise, now I have three 16GB USB sticks and I couldn't tell you what's on any of them!
I want something like floppies again: a similar, flat form factor, a wide range of capacities from a few hundred MB to GB or even TB.
I suppose SD cards are pretty close. maybe I just need a better storage solution for them, some kind of larger card I can clip them into and write a little label on to remind me what's on there. Hmm…
The original Shugart interface only had one shared motor enable line for 4 drives, and usually all drives connected to the same cable would spin up simoultaneously when this was activated. By replacing a Drive-Select line with an additional motor-enable, IBM solved that problem as well.
Why are floppy cables twisted? Hmm...their parents didn't love them enough? Oh, wrong twisted. lol
I had assumed Cable-Select used something like echoes in the wire to define the position (a single ping meant tip, two pings meant middle)
Don't know why I watched this video since my computer uses USB 3.0 and no disk drives lol..... Much less floppy drive
wow...I thought it was just to make it easy to determine which plugged into floppy and which plugged into hard drive with a quick glance LOL
So it's explained now when ide has been gone for 10 fucking years and floppy's even longer
what a twist
th-cam.com/video/ag1vabERNn0/w-d-xo.html
Um.. Because different wires go to different places?
I don't know what the problem was really. It was super easy to configure drives. Using jumpers and flat cables made it simple to cable manage and use the shortest cables. Every twisted/select cable always looked like a rats nest in the with drives in the wrong spots.
Weird. I always used CS setting on IDE devices. At least since UDMA/33. On older devices I used M/S.
I find it odd that they did this with floppy drives but generally not with hard drives. You have to use a jumper to indicate the primary IDE drive anyway, so why is cable select for the floppy drive worth bothering with?
I quickly learned to hold on to all jumper connectors I could, as they would quickly get lost, and I think I still have some in my screw box.
Changes in technology sometimes bear a resemblance to biological evolution, and this is a fantastic example! This simple but effective solution by a subtle manipulation of what is already there is exactly the sort of solution genetic evolution would stumble upon.
Okay so why can't we get rid of the concept of drive letters like Linux and Unix or BSD systems?
A/B drive flip, just like cable select mode on IDE drives.
I was in an electrical engineering college course (Ontario Canada) , that up until 2006 required ALL projects and assignments to be submitted via FLOPPY DISC ! YES, 3.5" floppy discs ! After 2007 everything went to online submissions. Even as early as 2006, many people simply didn't have floppies on their laptops, so they had to copy stuff to a USB drive, then use one of the school's lab room computers to copy their files onto a floppy, and then submit that in for marking. I have a stack of old floppies, and even a package of floppies unopened (a museum piece), as well as 2 external USB floppy drives. Never know when that might come in handy, right? Floppies make good 'COASTERS' for cold drinks on a hot humid day.
The original Shugart 34pin floppy interface had 4 Drive select leads, DS 0 to 3, and it was common to see these jumpers on drives. A lot of 8086/8088 IBM Compatabile PCs were quite capable of supporting 4 separate floppy disk drives.
This was abandoned later, certainly when 286's came along as the IBM version did not support it. In fact, Drive B: stayed as drive 1 and drive 2 on the lead became A: Drive 0 was repurposed into Motor start and drive 3 dropped completely. The twist would not have worked with the original Shugart pinout
BTW your 5 1/4" drives are inverted in the animation, and you put the disks in the right way up....
Never used CS for IDE. Also, long ago, reading about the floppy disk interface I was shocked about data being SERIAL and not PARALLEL like in the IDE / ATA interface. I dont recall why but they use more control cables than IDE.
There's a suprising amount of history to serial data transfers, there was quite the back-and-forth. Before the Universal Serial Bus (USB) there was Parallel Port, but before that was the Serial Port.
I would not be surprised if there's a common history between the floppy ATA interface and the serial port honestly.
The short answer: because they control drive access and since the drives are "dumb," they need a different set of pins grounded to tell them what to do (top row instead of bottom).
In the years before IBM had PCs (1970s) most drives were selected by jumpers on the drive as shown, except that a total of four drives were available. This includes bot the 5 1/4" predecessors to 3.5" disks as well as the original 8" floppy drives. The ability to add floppy drives was more cost efficient, even at $500/8" 128KB drives, than $3000 for a 14" 20MB hard drive that would crash if you stared at it too hard. :D
Cromemco was actually the first company I saw to use the cable twist idea on their C-10 computer, except they used single drive external units with separate custom cables similar to GPIB connectors. Their system allowed new drives to just be connected to the back of the previous drives' connection.
Going back to this era of tech.. you touched on the floppy, but how about the same thing on the old MFM/RLL/ESDI hard drives, which shared a control cable, but each had their own DATA cable.. not to mention dealing with terminating resistors! Remember running a confg program to set your drive type? 1=10meg, 2=20 meg, etc..
If I remember corrrectly, that not the full truth. Pre-IBM disk standard (Shugart ?) hat 4 "drive select" wires/pins, but only one "Motor On". So all 4 drives had to rotate simultaneously.
IBM not made drives "configurationless" but also had two separate "Motor On" signals for each drive at motherboard/controller card side.
something you neglected to mention is this. even with the twisted cable, you were able to refer to the a: drive as b: as well. this is how you copied things from one floppy to another without having either a second floppy or a hard drive. you simply typed in the command copy a:name.ext b: . depending on the size of the file, you might have to swap the two floppies in and out several times. it depended on how much memory you had, up to the maximum of 640KB. I actually feel sorry for pc users, because as a cp/m user, my 8" double sided double density floppy drives would hold up to 860KB each. then of course I "upgraded" to a generic pc/xt and lost that advantage. of course the 5.25" floppy eventually upgraded to the high density 2.8MB and the original 3.5" 760KB floppy upgraded to 1.44MB. you also neglected to mention that the b: card edge connector could be used as a tape drive connector. I look forward to reading your response.
Well, I have the answer to your question. Its like this. If you study the gray cover of your cable you will see that your seeing rough covering over a row of circular apertures. And on your board is metal pins. Thats because on the inside of your IDE cable is a group of metal wires. The gray substance seals them together as well as seals the electricity in. They are traditionally SOLD as 1, but the plastic can tear under pressure. The jumper DIP switches are for grounding and the position when reported back to the Motherboard assigns it a DRIVE in the CMOS configuration. You can still overide the drive standard and change drive signing if you wish within managing your CMOS and your JUMPER dip switches there after the standard which becomes necessary sometimes and a pain. But mostly we just change for MASTER and SLAVE drives no more.
Lol, schlepping it with a 40wire IDE cable? Gonna need 80wire PATA if you want to burn a DVD... too much crosstalk and interference on those old 40's.
J/K, never knew about that twist... or that missing bit of wire on the HDD cables either.
Hello, can You make a video to explain the diffefences betwen (ata100) and (ata133) or Uata133 and there was one more this with the ide cables (40 pin ide, 44pin ide and 80pin ide) i remember back in the (Pentium) time that my PC can recognize the cable that i was using like ide40 or ide 80 and i'm curious what îs the difference betwen them. Thank You :)
Wait.... So this is why floppies are always "A:" on windows & DOS, and the HDD starts at C by default? And then Presumably B: is the B-floppy drive....
I had to make a VooDoo 2 SLI cable using a floppy cable, because they were impossible to find online. I read you just need to cut a floppy cable to 2-3" length and re-attach the connector, but it turned out to be a fucking nightmare. Tried over 10 times before I got it right. Has to be connected perfectly or it doesn't work. I made 4 on the bounce in case they broke. So far, 5 years on, and the original still works.
Ok, so this is actually a good thing. Was trying to mod my Windows 10 pc the other day by adding a floppy drive out of an old computer, but gave up, because I thought I needed a new cable. LOL. Thanks for the tip!
For some reason this made me remember something I was pondering ages ago. Quite a few years back I got a USB floppy drive to use with an old ultraslim laptop that didn't have a FDD built in. If I plugged this into a PC that already had a floppy drive it would start up with drive letter "B". I often wondered what windows would call the USB FDD if I plugged it into a PC that already had two floppy drives installed, But I never got around to trying it to see....... Did anyone here ever try this?
The actual reason was IBM's recognition of the fact its customers were not sophisticated enough to grasp the concept of "drive 0"... just set them both as "drive 1" rather than "drive A:" as 0 and "drive B:" as 1.
The aging geek in me is cringing... at 0:55 that cable isn't installed all the way.. and then at 2:39 (and again later in the video) the floppy drives are upside down! Sorry.. just feels wrong! :-) Otherwise great accurate info from "Back in the old days" :-)
Which in turn kinda brings up why hard drives, even today. Remains C: and not A: or B: ... Hardware and software was designed for A nd B to be floppy drives and floppy drives only for a long time. For backwards compatibility, the first hard drive partition remains on C:, even when there are no floppy drives nor controllers around at all.
I would also like to point out that drives can be assigned by the OS as well. In a DOS 6.22 system with one drive, if you attempt to access the B drive, the Os will ask you to insert a disk into drive B, and when you continued, it would access the single floppy as drive B. Attempting to access drive A again would set the floppy back to drive A.
I always assumed it was a nod towards Chubby Checker.
Wow, years after I drop IDE stuff for SATA, and only now do I realize I didn't have to set those jumpers for IDE Hard disks and CD drives if the cable had that notch for the master/slave detect, I'd still end up at least mastering one drive and then have the other drive select what ever (unless it only provided Master and Slave options)
Watching this on a machine that actually has a jumper on it's floppy drive.
First of all I consider myself an ignorant in computer stuff, and always have.
Then again, if you know how to open control panel today you're considered a knoledged guy, and if you know how to change your os and partition your drive, youre considered a god among mere mortals by the average person.
I miss the old master slave jumper required system because when people watched you use them they were all flabergasted, it was extremely simple and easy but locked like you really knew your stuff.
So in 2017 I finally managed to understand what that CS jumper position was good for... Better late than never...
I could never get cable select to work with IDE drives and ended up just setting master and slave using jumper pins... thank god for SATA.
So, basically, instead of having a switch on the drive, they had a tiny piece of metal inside a tiny piece of plastic that shorted out two connectors. You know, exactly like what a switch do.
But in 1900's electronics, it would only make sense to have a switch with labels, so they disregarded that idea. And then hundreds of manufacturers raced to find the most elegant solution to a problem that most everyday users wouldn't have.