19 Nov
1997
19 Nov
'97
11:54 p.m.
On Wed, 19 Nov 1997, Daniel A. Seagraves wrote:
-tony
There's a few slots up by the CPU labled MUD. I
think I know what it
MUD = Modified Unibus Device
Also, SPC = Small Peripheral Controller
means. But I want to make sure. Does it mean
Modified Unibus Device?
And does that mean DMA slot? And does that mean all the screwing with the
backplane I did was unneccesary?
A MUD slot means that the memory address/data bus is wired on the A/B
connectors (which are not used on a true SPC slot). On an 11/34 the memory
bus is just the Unibus, but on something like an 11/44 there's a 22 bit
address bus for memory. The C-F connectors will carry the Unibus signals,
just like an SPC slot
I think all MUD slots do carry the DMA signals, but on the SPC part. You
do still have to cut the NPG jumper from CA1 to CB1 (I can't think of a
way to make a unibus slot where that's not that case that will work with
all unmodified cards).