16 Jul
2002
16 Jul
'02
1:11 p.m.
Hello again, Patrick,
another question that was not yet answered:
Yup, from 4kW to 32kW, there's some description of the differences here:
http://www.not-compatible.org/PDP-11/modules/msv11-d.html
However, it doesn't tell me what I need to look for in a RAM IC for it,
like if a standard 4116 or 4164 will work (possibly grounding extra
R/C address lines on the 4164...) There's a total of 32 memory IC's, all
non-standard looking part numbers on the MSV11 I have.
Last night, I finally made it into the basement to dig out something
like this. Found a M8044-DC (obviously a MSV11-DD) and a M8044-DF
(apparently also a MSV11-DD). Both have regular 16k*1 chips in a 4*8
array. I didn't find a difference between M8044-DF and -DC (rev level,
perhaps?), aside from one using ceramic Hitachi chips (HM4716A-3) while
the other has plastic Fairchild ones (MB8116E).
If you're interested, I took a couple of pictures before storing the
modules back. Let me know if you want them (~40kB * 6 .JPG files).
Besides replacing the DRAM chips, you'll need to fiddle with some
jumpers and maybe one additional resistor in order to convert a MSV11-DB
to a MSV11-DD. There's some information in my 1981 "d|i|g|i|t|a|l
microcomputers amd memories" manual that will certainly help. 20 pages
in total, with lots of tables, block diagrams, and functional
descriptions. No complete schematics, but might suffice to do the
conversion. A scanner is nearby. Want me to...?
--
Andreas Freiherr
Vishay Semiconductor GmbH, Heilbronn, Germany
http://www.vishay.com
Also, is it possible/easy to change the M8044-BB board
(8KW?) to have at
least 16KW if not 32KW of memory? That'd be a nice upgrade for the
machine if I can do it myself with 'stock' DRAMs.
I have no docs available here in the office, but I seem to remember that
the M8044 (MSV-11?) was available in several flavors (identified by the
letters after the dash) with different capacities, so it might be
possible. I'll look up more about this at home. There should be boards
to examine. Stay tuned.