Re: Did Commodore cheat with the quad density floppies?

Den Tue, 8 Jan 2019 18:06:39 +0100 skrev Gerrit Heitsch
<gerrit@laosinh.s.bawue.de>:
> On 1/8/19 6:00 PM, Mike Stein wrote:
> > A question for those folks who think that the twisted cable was a
> > hardware-crippling hack by incompetent "engineers":
> > 
> > IDE drives & cables essentially did the same thing, modifying the
> > cable by cutting one wire so that CS could be implemented.
> > 
> > Is that the same thing? 
> 
> No, it's not since you could still use the jumpers on the drives to 
> select which one was Master if you wanted to. Also, since the drives 
> didn't have to be accessible from the outside, it didn't make much of
> a difference where you put which.
> 
> With the floppy cable with the twist you had no choice, drive A was 
> alwas the one on the end of the cable.

Except if the cable had two twists like the original IBM PC, then drive
A were first, which makes the left drive (as seen from the front) A and
the right drive B if you have two full height drives. Logical for
everywhere in the world where people read from left to right.

A cable with only one twist fits perfectly in all those various size
tower cases, as the mother board would be down below and the uppermost
drive would be at the end of the cable.

As most people are right handed, having the drives to the right makes
sense, thus IBM could hardly have flipped the inside of the PC back in
1981 even if they had predicted that tower cases would be a thing in
what then was the future.

There were IIRC actually smaller tower cases which were flipped "upside
down" as compared to most tower cases, with the PSU and drives near the
bottom and the mother board near the top. Those tower cases could share
the same type of cable as the original destop PC cases and still have
the A drive to the left or on the top, and the B drive to the right or
down below.

I don't really think it's a big issue that you would need two different
sets of cables depending on which type of case you had. When tower
cases started to be a thing they were equipped with hard drives anyway,
so the only usage of two drives were to have both a 3.5" and a 5.25"
drive and then A/B didn't really matter that much any more.

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