18 Mar
2005
18 Mar
'05
10:14 a.m.
1) I found the parts-layout and parts list and have
been able
to identify most of the missing chips, except for the
one labeled "E63" in the parts layout schematic,
near the center of the board. This chip is not explained
in the parts list. Does anybody know what it is?
(it is the 18 pin chip to the left of pin 1 of the lower D3-6121-9A
chip, which in turn is the lowermost of the four 40 pin DIP chips
by Harris; this is when looking at the component side with
the slot tabs pointing downwards)
Mine has an empty socket there. Looks from how it is wired that it is meant
to take another m1-6322-9, like the three above it. (Perhaps an option
ROM?)
2) Can one use this board to run older pdp8 software?
Yes (some).
Can one connect a terminal to the printer port with
some special cable, supply power to the board and
have the thing come back alive and talk to the terminal?
I don't think it wants to talk there (without extensive firmware work). It
wants to plug into the terminal backplane (which I am sure is *not* qbus),
with a keyboard plugged into it.
I don't have a qbus backplane, so I was just
thinking about
repairing the board, repopulate it and connect power at the
appropriate points.
From what I have read, that could be a challenge. It
would probably be
easier to build a compatible video adapter and keyboard stuff for
it. The
floppy is an RX01 with a special cable, IIRC.
Vince