vt278

[vrs]

> 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