On Wed, Feb 15, 2017 at 1:57 AM, Noel Chiappa <jnc at mercury.lcs.mit.edu> wrote:
From: Tony
Duell
Having other hardware decode instructions that
appear as NOPs to the
main processor is not uncommon in HP machines.
Ah, so you actually had some prior knowledge that helped in working out that
puzzle, that that's what's happening here! :-)
Nothing that isn't now available to anyone, like 'my' schematics of
the 9825 memory
boards, the HP41 machine code programming info (think of things like the printer
controller IC), etc.
-tony