On 6/27/2006 at 7:11 PM Jim Leonard wrote:
>> I was *all over* IBM until PS/2. "I
can't put my existing boards in it?
>> Why the hell not? Who made *that* stupid decision?
What makes you
think this was a "stupid decision"? The MCA bus was
capable of *40MB/S*, which at the time was rather remarkable. ISA is
amazingly slow. And the business desktop market wanted smaller
machines. Part of the intent of MCA, however misguided, was to
eliminate DIP switches and jumpers, which were causing a lot of support
calls. With the config files for MCA, that was to suppose to reduce
The only real malfunction of the MCA bus was that unless the cards
were made to very precise standards (and I think the tolerance was 1 or
2 mils, according to the design guides), improperly positioned cards
could smoke a machine.
MCA prototyping cards were available for about $40/ea. And unless
you wanted to do the really high speed stuff, a couple PALs would
suffice. Unlike PCI which requires a FPGA for any kind of bus
compatibility (although I have seen some PAL-only designs for really
Everyone seems to think every damn card, bus, and system made should
be backwards to the AND gate. Get over it, move in to the 90's. At the