Re: Did Commodore cheat with the quad density floppies?

On 16/05/2019 14:17, Mia Magnusson wrote:

> The SCSI controllers performance were probably better over MCA than
> over ISA, but a multi serial port could technically be just as good on
> ISA as on MCA.

It would likely require more cpu and just touching the isa bus will slow
the cpu down.

> Trying to fit an ISA card in a
> MCA slot would cause havoc, while ISA cards did fit in EISA slots.

You're talking about back ward compatibility, which is like claiming
S-VHS is better than DVD because VHS tapes will work in an S-VHS player
but if you try to jam it in a DVD player then something will break. I
accept there is value in backward compatibility, but history has shown
us that people were willing to throw away their ISA boards. Maybe just
not at that particular point in time.

> Were there any PS/2 that didn't have some graphics on board?

I try not to make claims about "all" of anything unless I am absolutely
sure.

> One thing worth remembering was that in the beginning only small/new
> companies dared making PC compatibles (Compaq and Columbia).

I think it's more "bothered" than "dared". The IBM PC was not initially
considered to be something worth copying.

The Apple 2 was doing pretty well, there were clones but not many. Why
would anyone admit that their computers weren't good enough that they
would have to copy someone elses?

It was always going to be the smaller companies looking to make a quick
$ without putting in the R&D that would come in and copy the PC.

>   The IBM AT was mostly rather obvious,

Quite a lot of the architecture is non obvious, the chaining of the irq
controller, the bios extensions.

It does make sense to jump on it, so why does it not make sense to jump
on the next one?

> The fact that you had to fiddle with various setup diskettes and stuff
> to even get the computer to run MS-DOS with a new card installed
> probably led people to think that MCA was just as much hassle as ISA
> was.

I remember the floppy disks, in hindsite they were a bad decision.
However it wasn't like there was a load of OS that could deal with
configuring the cards that would have told them it was a bad decision.
Back then the only one I came into contact with was Zorro on the Amiga.

I'm not saying MCA was perfect, just that it did have avantages over ISA
and it wasn't just invented as a cash grab.