floppy drives and cables

[J. P. Gilliver (John)]

In message <ougql9$m6u$1...@dont-email.me>, Paul <nos...@needed.invalid>
writes:
[]
>The twisted part, consists of four active signals.
>Two for each drive. The twist swaps the signals, so
>that one connector can have an A personality and the
>other a B personality. (Just like a CS Cable Select method.)
[]
I've always assumed it was that, and thought it was a clever solution
(admittedly, requiring unusual cable construction).

So presumably there is something like (_at the drive_):

01 - A
10 - B

(or vice versa).

Does that mean there is the _possibility_ of _four_ drives, using up the
00 and 11 options?
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

I reckon in a few years we'll have GoogleBum. You'll type in someone's name
and it will show you what their bum looks like. Even if they've never posted a
nude picture, it will reconstruct their bum from bits of their face and leg
and whatever else they can find. - Charlie Brooker, RT 2014/12/13-19

[ja...@nospam.com]

On Wed, 15 Nov 2017 14:16:24 +0000, "J. P. Gilliver (John)"
<G6JP...@255soft.uk> wrote:

>In message <ougql9$m6u$1...@dont-email.me>, Paul <nos...@needed.invalid>
>writes:
>[]
>>The twisted part, consists of four active signals.
>>Two for each drive. The twist swaps the signals, so
>>that one connector can have an A personality and the
>>other a B personality. (Just like a CS Cable Select method.)
>[]
>I've always assumed it was that, and thought it was a clever solution
>(admittedly, requiring unusual cable construction).
>
>So presumably there is something like (_at the drive_):
>
>01 - A
>10 - B
>
>(or vice versa).
>
>Does that mean there is the _possibility_ of _four_ drives, using up the
>00 and 11 options?

This is an unusual way of doing things, and making cables like that must
be difficult. I'd think it would have been easier to just have a
jumper(s) on the drive, for either drive A or Drive B. But this is how
they did it back then, and how it will always be.

I am curious if 3 or 4 drives could be used. Not that I would need that
many. I'm still trying to remember if those ZIP drives connected to the
floppy cable, or to something else, like a serial port? I had one, and
at the time it was the only way to store 100 megs on one drive, which at
that time was a lot of data. I had one of them for a brief time, but I
found they were unreliable. Flash drives sure are a better thing, now.

[Computer Nerd Kev]

In microsoft.public.win98.gen_discussion ja...@nospam.com wrote:
> On Wed, 15 Nov 2017 14:16:24 +0000, "J. P. Gilliver (John)"
> <G6JP...@255soft.uk> wrote:
>
>>In message <ougql9$m6u$1...@dont-email.me>, Paul <nos...@needed.invalid>
>>writes:
>>[]
>>>The twisted part, consists of four active signals.
>>>Two for each drive. The twist swaps the signals, so
>>>that one connector can have an A personality and the
>>>other a B personality. (Just like a CS Cable Select method.)
>>[]
>>I've always assumed it was that, and thought it was a clever solution
>>(admittedly, requiring unusual cable construction).
>>
>>So presumably there is something like (_at the drive_):
>>
>>01 - A
>>10 - B
>>
>>(or vice versa).
>>
>>Does that mean there is the _possibility_ of _four_ drives, using up the
>>00 and 11 options?
>

> I am curious if 3 or 4 drives could be used. Not that I would need that
> many. I'm still trying to remember if those ZIP drives connected to the
> floppy cable, or to something else, like a serial port?

The Zip drive installed in the PC I'm posting from is IDE. There were also
external ones for the parallel port and USB.

As for the drives, I guess a lot of things are possible if you write
the code to access them from scratch. Whether this method for selecting
more than two drives would work may depend on the flexibility of the
floppy controller.

--
__ __
#_ < |\| |< _#

[ja...@nospam.com]

Ok, I had an IDE Zip drive, and I also had a parallel port one.

Thanks

[Lee]

On Wednesday, November 15, 2017 at 7:17:34 AM UTC-7, J. P. Gilliver (John) wrote:
> In message <ougql9$m6u$1...@dont-email.me>, Paul <nos...@needed.invalid>
> writes:
> []
> >The twisted part, consists of four active signals.
> >Two for each drive. The twist swaps the signals, so
> >that one connector can have an A personality and the
> >other a B personality. (Just like a CS Cable Select method.)

Only two pair of signals with one pair of them being /motor_on, I disremember the other. So only two drives possible. /Drive_select? eg. 'I am shining my light at you.'

> []
> I've always assumed it was that, and thought it was a clever solution
> (admittedly, requiring unusual cable construction).
>
> So presumably there is something like (_at the drive_):
>
> 01 - A
> 10 - B
>
> (or vice versa).
>
> Does that mean there is the _possibility_ of _four_ drives, using up the
> 00 and 11 options?

As above no, even though it used to be
00 - A
01 - B
10 - C
11 - D

Floppy drives were very expensive and little utility was gained after two and an overpowering need to settle the faster and much larger hard drive in as drive C and D led to the extinction of more than two floppy drives.

But some 5 1/4 floppy drives have jumpers for those higher numbers and ALL using the twisted cable method must be jumpered to be drive 2 or drive B or drive 1 in a zero based counting system. Replacement drives sold new for the last 20 years or so will have the jumpers missing but the block where they used to be soldered to be set for drive B while a few have no jumper block solder pad to hack on anymore at all.

You would have to rewrite the BIOS in order to enable a 2nd floppy on this 2005 Dell even though they are using the twisted cable for Drive A, the BIOS has no provisions for Drive B as a floppy.