2 Apr
1997
2 Apr
'97
6 p.m.
Can anyone enlighten me on the following?
>(1) M8330
PDP8/e Clock Generator/Timing logic. Part of the CPU board set (along with
M8300 and M8310, which are the data path and control in some order) as you
guessed
>(1) M8349B K-SP-MR8FE-1 Rev F M1 1k prom
board
>(1) M8349B K-SP-MR8FE-1 Rev F M2 1k prom board
>(1) M8349B K-SP-MR8FE-1 Rev F M3 1k prom board
>(1) M8349B K-SP-MR8FE-1 Rev F M4 1k prom board
>
>The prom boards have Intel 1702A eproms on them, but they are soldered in.
They are 1K * 13 bits (!) of EPROM (7 off 1702s), + an optional 256 12 bit
words of RAM. The idea is that if the 13th bit of a word is clear, then
the processor sees the other 12 bits of that EPROM location. If the 13th
bit is set then 8 bits of the EPROM data select one of the RAM locations,
which can be read/written by the CPU. It basically gives you 1K of EPROM
with the ability to have some changeable locations in the middle of it.
I am pretty sure the first is one of the processor cards from a PDP-8/e,
but I have no idea what the other boards are for.
The 1702As, as noted, are soldered in, which makes me think that
this was more than just a generic, burn-your-own-ROM card set.
You'll notice there are _8_ edge plugs on these boards. The bottom 4 (away
from the EPROMs) go into a normal Omnibus slot. The top
4 take 4 little
shorting blocks that link the pins on the solder side to the pins on
the
component side. The pins on the component side are linked to the EPROMs,
those on the solder side to the rest of the logic. To program it, you pull
off the shorting blocks and link up a special programmer to the top
connectors.
AFAIK it was just a generic ROM board. The PDP8/e Maintenance Manual
Volume 2 covers it, but doesn't AFAIK mention any versions for specific
applications, like bootstraps.
On the other hand, the set of 4 boards you mentioned just might contain
some standard code.
William Donzelli
--
-tony
ard12(a)eng.cam.ac.uk
The gates in my computer are AND,OR and NOT, not Bill