SQ703/6 conversion and a little fun

Nigel Johnson Ham g4ajq1 at gmail.com
Mon Nov 1 16:25:07 CDT 2021

A few months ago, thanks to help from several people here, I converted
an SQ703 TMSCP controller to SQ706 MSCP.

I had problems trying to use it on the vax due to the complexity of
mapping Q-Bus registers under ODT, so put off trying until I got the
LSI-11/73 going.

Now I have a problem: It seems to run and recognise the controller as
SQ706 according to the on-board diagnostics, however it insists saying
it is at 777450, the TMSCP address.  Trying to change it gives me an
out-of-bounds message.

OK, I thought, I will just use it there.

Put it in to a running RT11 system and it shows up at 772150 and clashes
with an existing controller!

It seems that one of the PALs is maybe setting up the address!

Anybody else tried this?



Here's the fun: 

Maybe our vax computers will become popular once again!

Amateur Radio, the origin of the open-source concept!
Skype:  TILBURY2591 nw.johnson at ieee.org

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