scd and mcd

[Warner Losh]

On Apr 23, 2011, at 5:19 PM, perryh at pluto.rain.com wrote:

> Warner Losh <imp at bsdimp.com> wrote:
> 
>> mcd and scd are ISA-only devices ... They were important for the
>> 386 (now not supported) and 486 machines.  Since the 486 machines
>> in question maxed out at 32MB, and 8.x has trouble running in 32MB
>> on x86, I'm guessing there aren't too many 486 SX/DX machines
>> running 8.x.
> 
> 486 were the last for which ISA was the primary bus, but ISA was
> still present (bridged from PCI) on most Pentium systems and common
> at least as recently as Pentium-II.  (I don't have a disassembled
> P-III handy to check whether it has an ISA slot.)

Most Pentium II and newer systems had IDE connectors on the motherboard.  Many of the Pentium I ones did too.  Only if you didn't have IDE connectors on mobo would you be likely to consider one of these CD's.  Also, I think they topped out at 4x or 8x speed since they had a custom interface.

Warner