11/04 Project

[JCWelch]

 CLR
 765000
 LAD
 EXAM
‘Bus Err’ light comes on.

CLR
 765020
 LAD
 CNTRL+START
Display changes to 165020 
Nothing on the terminal.

Do you know which color wire (red, clear, black) goes to which festoon connector (TP1, TP2, TP3, TP4)?
Don’t want to blow anything up.


Sent from my iPad

> On Dec 13, 2017, at 9:37 PM, Noel Chiappa <jnc at mercury.lcs.mit.edu> wrote:
> 

> 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