19 Aug
2015
19 Aug
'15
9:14 p.m.
On Aug 19, 2015, at 3:33 PM, dave at mitton.com
wrote:
From: Paul Koning <paulkoning at comcast.net>
For the KMC, you?d have to understand enough about that machine?s microcode to see how to
make it request an interrupt. For the DMC, in addition you have to find out how to get
that device to execute a KMC instruction handed to it in a CSR ? something that wasn?t all
that obvious though it can be deduced from the manuals if you work at it.
> ...
Ok. RSTS does indeed check for duplicate vectors.
It also checks for devices interrupting at too high a priority.
It?s pretty neat code. Back in 1977 or so when
that came out, it may have been one of the first autoconfig systems, at least in DEC. It
could probe almost all devices supported by RSTS (and some not supported); the exceptions
being card readers and the DT07 bus switch. But it would do hairy things like the KMC-11
and DMC-11, for example.
Wait? What was tricky about KMCs and DMCs? They used the same algorithms, I had it down
cold at the time. Speaking of which, I have one copy of the KMC-11A
Programmer's Guide if anyone needs it or would like to scan it?
There are a couple on Bitsavers, but yours might be different from what is there. Worth a
look.
paul