26 Aug
2012
26 Aug
'12
2 a.m.
We are debugging an interrupt problem with the PDP-8/I
at the RICM.
Today we found that the INT RQST signal is not routed through the M117
module in slot F11 as shown on page 7 in the
PDP8-I_CPU_blueprints_1969.pdf.
Does anyone have a set of prints where page 7 is older than revision L?
Yes. I have a schematic in which INT_RQST goes to F21D1, F_SET goes to F21E1,
and the result from F21F1 goes to the flip-flop at E33J1.
The ECO added KEY_LAEXDEP_L to the NAND, which required the M117 instead
of the M113.
The PDF is called "dec-8i-hr2a-d-pr (PDP8i Schematics -- OLD).pdf" on my box,
but I'm not sure where I got it.
Ah. I found it here:
http://pdp-8.org/scans/highgate/pdp8i-docs/dec-8i-hr2a-d-pr.pdf
Hope that helps!
Vince