13 Dec
2017
13 Dec
'17
7:37 p.m.
From: John Welch
Anyway, 'a' comes over as 000141 and
'A' comes over as 000101.
Good, the console is working.
CLR
LAD
DEP
OK, that loads a '0' (halt) in 0.
CNTRL+INIT
CNTRL+START -> reads 000002
OK, so it reads the HALT at 0 and stops.
CNTRL+BOOT -> Run light is on, SR Disp light is on
CNTRL+HLT reads 173150
Sounds like it may be looping in the high bank of ROM? That's not necessarily
wrong.
I finally figured out what the ROMs in the M9312 do; the ROMs at 765000 are
the first-level diagnostic, and the console. The bootstrap code for the
various devices is at 773000.
773024 LAD, 773000 DEP, BUS ERR light comes on.
That makes sense; you can't write to the ROM.
Any suggestions?
i) Check the ROM contents; there are two kinds of M9312 console ROMs, one for
most CPUs, and one for the 11/60 and 11/70, see the tech manual for the
M9312.
So read out the first couple of words:
CLR
765000
LAD
EXAM
EXAM
etc
and let's see what they read.
ii) Try starting the console code directly:
CLR
765020
LAD
CNTRL+START
I have other M9312s I could try.
Can't hurt.
Noel