Which RT-11 for an 11/03

Mattis Lind mattislind at gmail.com
Thu Mar 10 13:15:08 CST 2016

2016-03-10 18:51 GMT+01:00 Richard Cini <rich.cini at verizon.net>:

> Is there a listing somewhere of what versions of RT-11 work with which
> CPUs? The Heath H11 uses the LSI-11 which I think is an 11/03 equivalent.
> Is there a specific version (or maximum version) designed for this CPU?

I have been using RT11 v5.3 on a LSI-11/2 (KD11-HA / M7270) machine with
RX02 and 64kByte memory. I also tried RT11 V3B / MU-BASIC on this machine
booting from RX02.


Long ago I ran RT11 V4 on a VT103 with LSI11/2 CPU and dual TU58. It was
really very slow. I have the distribution kit somewhere on original TU58
but I am not sure about the state of those cassettes.

So I am pretty convinced that the it should work. What about SimH or
Ersatz-11? Does your image boot on those simulators if you set the up
identical to your setup? I know that SimH had problems booting from TU58
but as far as I remember that should have been fixed. Try the latest SimH
on Github.

Do you have enough working memory in your system? Have you ran diagnostics?
Maybe it is a good idea to create a bootable TU58 with XXDP. If you use
SimH you can create your own bootable TU58 without to much effort. I did
this when working on my 11/04. Use one of the RL02 images on bitsavers and
try to follow the guide I have a bit down on this page:

> I tried v4 using a method I found on-line (modifying with SIMH to make it
> bootable as a TU58 image rather than an RK) but it doesn't work so I wanted
> to first eliminate the system version as the potential problem.
> Thanks!
> Rich
> Sent from my iPhone

Good luck!


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