1 Oct
2014
1 Oct
'14
11:46 a.m.
On Oct 1, 2014, at 2:06 PM, Mark J. Blair <nf6x at nf6x.net> wrote:
On Oct 1, 2014, at 09:01 , David Riley <fraveydank at gmail.com> wrote:
Well, in the 11/44 at least it's used as the bus that the CPU and memory
sit on; only the AB slots at either end of the backplane are standard
Unibus. It's similar in the 11/34. In the 11/44, the console interface
module (an 8085 micro which performs the functions formerly delegated
to the front panel) and the bus jumpers and terminators are the only
things that occupy standard Unibus slots; the modified Unibus is mainly
meant for memory (thus the core voltages).
Typical Unibus peripherals are quad-width; those that are hex-width are
*generally* only in it for the additional power, not unlike quad-width
Qbus cards that don't use the CD bus. There are certainly exceptions,
but I don't know what they are.
If someone is trying to build Unibus memory, they'll probably be
interested in the modified Unibus pins. Otherwise, it's somewhat
unlikely.
- Dave
Nice work! Very handy. One suggestion: you
might want to split out the
"common function" common to one that doesn't include modified Unibus;
assuming you're only developing peripheral cards (not a guarantee),
you can get away with significantly less HV and -V capable pins if you
ignore that (at the user's peril, I guess).
Where is the modified Unibus used? I've forgotten since I first composed the
spreadsheet several months ago. I tried to cram in every bus I could find using the same
physical form factor, but if MUD is an especially niche application then maybe it
doesn't need to be in there.