Microvax II

From: ajp166 <ajp166_at_bellatlantic.net>
Date: Fri Oct 13 18:05:17 2000

From: Neil Cherry <ncherry_at_home.net>
>BTW is it easy to design boards for the Microvax. This Analog board
seems
>really simple. Designing an intelligent SCSI board wouldn't be a lot
more
>difficult (I didn't say anything about the Vax driver).


MVII is a Q-bus machine and like it's compatable Q-bus PDP-11s that
went before and during its a reasonably easy bus to interface to and
DEC did a fair job of makeing the documentation for it easy to get.
Designing a PIO SCSI card would be easy, DMA a bit harder but
there is no secrets there either. Programming is another thing though
as the Q-bus is an annex of the processor address space and DMA
between memory (on private(PMI) bus) and QBUS devices is more
complex programming. However RQDX (disks), DEQNA/DELQA (NIC)
do the dma trick so that is already known.

Allison
Received on Fri Oct 13 2000 - 18:05:17 BST