PC floppy cable twists...

Fred Cisin cisin at xenosoft.com
Thu Oct 20 17:12:59 CDT 2005

On Thu, 20 Oct 2005, Jules Richardson wrote:
> ... discussion about this on another list got me curious - what *was*
> the point of that cable twist in a (IBM clone) PC floppy cable, when
> every other system on the planet was using straight-through cables?
> 2) when the twist was introduced, there were presumably no clone
> machines around (it was there from day 1 IIRC) - and wouldn't the
> addition of a second floppy drive to an IBM machine have been a field
> service call anyway? So it's not like it was the general public changing
> jumpers, but a trained engineer...

IBM sold through Computerland, Businessland, and a few others.
They had to simplify it enough that Computerland "technicians"
could add a drive without damaging anything.

SOME Computerland technicians were competent.
Some others failed entry exams at Fry's.

> figure out. If a customer tried to add their own drive rather than
> buying through IBM, surely IBM couldn't care less if they struggled to
> figure the drive jumpers on their 'non-standard' unit out?

When somebody adds a B: drive, they could blame IBM when the A: drive
would no longer work.

> It's got me curious as it seems like a hack that doesn't completely
> solve any kind of problem whilst introducing a difference between IBM
> and the rest of the industry.

. . . and you were looking for a REASON?

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