[HECnet] New Digital Unix node TIGER on HECnet

[gerry77 at mail.com]

On Sat, 5 Jun 2010 15:54:20 -0400, you wrote:

OK, you tried playing nice -- so now play dirty!   If you never found a way
to make NULJOB (or whatever TOPS-10 has for an idle loop -- I've never been
into the sources) identify itself to KLH10, why not hack up KLH10 to detect
NULJOB itself?

Well, this approach has various issues that have to be considered:

1. first of all, we do not know anything about PDP-10 machine code, so it
would be quite difficult to pin down the exact instruction sequence that
would tell us the OS is in its idle loop. And then there must be someone
quite proficient in C language who should modify the emulator (i.e. not me).

2. I have some very faint memories about difficulties in tracking down the
TOPS-10 idle loop (or it was TOPS-20?). That is it does not make something
easily identifiable by just analyzing the actual instruction stream. I must
have read something about this topic somewhere in the last three years...

3. Oh well, it would be nice to learn where is the culprit and how to
rebuild a TOPS-10 monitor from scratch! :-) Now I've posted a request to
alt.sys.pdp10. Let's see if someone will explain me what to do.

Some misc bits:

A nice post about the (dis)advantages of modifying either the emulator or
the OS: http://groups.google.com/group/alt.sys.pdp10/msg/c1c8e09d247595ce

A description of the special KLH10 idle device. At the end of the document
there is also a brief explanation about where to put the needed monitor
patches: http://www.avanthar.com/~healyzh/klh10/doc/dvhost.txt

Bye,
G.