30 Apr
2015
30 Apr
'15
9:55 a.m.
On 2015-04-30 17:06, Noel Chiappa wrote:
I thought I had seen the sources of the bootstrap code in some document.
Did I just imagine that?
I hope you also are aware that both the M9301 and the M9312 have
different boot roms for some machines. I know that the 11/70 use
different roms with other tests than other PDP-11s, and I seem to
remember that one or two others do as well. (The 11/60 keeps popping up
in my brain...)
From: Jorg
Hoppe
> Here's what I have so far:
> http://ana-3.lcs.mit.edu/~jnc/tech/pdp11/M9301-YA.mac
Thanks for that effort!
Eh, de nada. Interesting and educational.
The M9312 code should be similar, at least it may
expose some ideas
Some parts of it (e.g. the CPU diagnostic) are mostly identical (and the
comments there, particularly on the single-op register instructions, are
useful to total understanding of that code in the M9301); but alas, I had
already done that part of the M9301 (at least, at a surface level)!
Much of the M9312 (including the functionality of most of what I had yet to
read in the M9301) was quite different. I did manage to get the 'print
number' code out of it, but that was pretty much it. So I've done a lot of the remaining M9301-YA code
(new version uploaded to
location above); not the per-device code, I'll probably blow that off, but
other than that, only a few tiny sections remain to be understood.
The per-device code are in separate PROMs that are used in both the 9301
and 9312. Those are the ones with the device code as constants in the
beginning of memory space for the PROM, by the way. (I seem to remember
someone mentioning this in the past.)
Johnny