On Jun 2, 2018, at 2:08 PM, Robert Armstrong via
cctalk <cctalk at classiccmp.org> wrote:
Tony Duell <ard.p850ug1 at gmail.com>
Incidentally, did DEC ever release any details (flowcharts, source listings,
etc) of the 11/730 microcode? And what about the control PROMs for the
memory system. The technical manual implies there was a listing of those,
but I've never found it.
I thought that DEC had a whole microcode development suite for the 730 to support
customer written extensions to the microcode, but I've never seen it nor any
documentation for it. If such a thing did exist then I seriously doubt anybody ever
bought it. The 730 was never a super popular machine to start with, and the market for a
customized version would have been very small.
Considering that the 730 was a 2901 based machine, and 2901s were widely used, presumably
the tools were not a problem around DEC. Perhaps they tweaked the UDA50 microcode
I've heard a persistent rumor over the years that
the WPS/8 and PDP-8 software group at DEC had modified the 730's microcode to support
a PDP-8 emulation of some kind, and that they used that internally for development
'cause it was faster than a real -8. I've not idea if that's true, but it
would be cool if they did. And no, I'm not talking about PDP-11 compatibility mode -
even the stock 730 had that (all the 7xx VAXes did, I believe).
The PDP-8 emulation used for internal PDP-8 software development was on an 11/60 running
RSTS/E, I remember that system in the lab in DEC Merrimack (MKO1-1). I would imagine it
could have been done on a 730 also but chances are the 11/60 was a whole lot faster.