25 Aug
2012
25 Aug
'12
6:21 p.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?
--
Michael Thompson
26 Aug
26 Aug
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
10:29 a.m.
On Sun, Aug 26, 2012 at 02:00:35AM -0700, Vincent Slyngstad wrote:
That is from the maintenance manual I have. The full scan of the manual
is here.
http://www.pdp8online.com/pdp8cgi/query_docs/query.pl?Search=hr2a&stype…
I have a paper copy of larger (C or D) prints and the sheet that matches above
is rev J. I don't have an easy way of scanning paper that large so they aren't
online.
Does anyone
have a set of prints where page 7 is older than revision L?
Ah. I found it here:
http://pdp-8.org/scans/highgate/pdp8i-docs/dec-8i-hr2a-d-pr.pdf
The ECO added KEY_LAEXDEP_L to the NAND, which
required the M117 instead
of the M113.
Do you have ECO information for the machine?
12:14 p.m.
From: David Gesswein: Sunday, August 26, 2012 10:29 AM
You may have been asking Michael, but I'll pretend you were asking me about the
8/I in general :-).
Only in the sense that I have "diffed" the schematics (manually) and noted the
ECO
history in the little box at the bottom. The notes I have say that this must
have
been all or part of either 8i-00002 or 8i-00020. Which is to say, this and a
change
to a pull-up are the only changes to this sheet, and the only new ECOs listed
for
this version of this sheet are #2 and #20.
Since the pull-up is just +3V(69), which is new to the gate change, both changes
probably belong to the same ECO, but I can't tell which number. (The other
number
may well refer to a routing change that wouldn't show on the schematic.)
I have 30 ECO numbers referenced, ranging for 00001 to 00099. Of those, I have
identified only 2 to the point of knowing what exact change was made and why.
Vince
The ECO added
KEY_LAEXDEP_L to the NAND, which required the M117 instead
of the M113.
Do you have ECO information for the machine?
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djg＠pdp8online.com -
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