gauging interest in VAX 6000-530

From: Eric Smith <eric_at_brouhaha.com>
Date: Tue Oct 26 20:28:56 1999

Allison wrote:
> I think you got that backwards. VME and 68k were synchronous. The PC
> bus is async (as is s100, Multibus, U and Q busses)!

No, it was right.

The 68K internally sychronizes the DTACK/ signal to a clock, but as far
as the bus goes, the clock is not needed. It's fully asynchronous. This
is explained very clearly in the 68000 data sheet.

On the other hand, the PC bus requires cards to either (1) operate at
the exact speed the computer wants, or (2) provide handshaking synchronously
to the bus clock.
Received on Tue Oct 26 1999 - 20:28:56 BST