20 Jan
2008
20 Jan
'08
10:40 p.m.
> I am looking for the simple wiring diagram to
connect a 33 ASR to a PDP 8. I
> have the 6 wire cable with the flat molex connector that goes to the PDP 8.
> The other end is just wire ends. I know that wires 2 go to 33's receive and 2
> to 33's send, the other 2 to the tape reader control, but not which ones. My
> color pairs are black/white black/red black/green if that is
> any help. But if I knew the molex pin layout, I could trace them back to the
> right connection on the 33.
The color pairs aren't what I'm used to, but hopefully you can trace them
back to the PDP-8 and find out what they are from that end.
Two documents which should help:
-The LT33 print set shows a basic PDP8-to-ASR33 connection on the second
page. Four of your six lines go to terminal lugs on the ASR-33; the other
two, for reader control, go to a relay card designated "4915" which gets
tied into the reader's power supply. Yes, there's instructions on where
the 4915 goes, though they don't really describe the 4915 to any useful
level. There's also a diagram of the "Mate-N-Lock" connector DEC used at
the time, which may be all you need - though your color pairs are
different from their description, so you may have to trace them out. The
LT33 doc is at:
http://www.pdp8online.com/pdp8cgi/query_docs/tifftopdf.pl/CHD/LT33_print_se…
The PDP-8/I Maintenance Manual has a drawing (figure 5-7, page 5-16) which
shows the PDP8-ASR33 connection in schematic form; it actually describes
the 4915 enough to be almost useful. :)
http://bitsavers.org/pdf/dec/pdp8/pdp8i/DEC-8I-HR1A-D_8Imaint_Mar70.pdf
Hope these help!
-O.-