It's been a while since my initial posting about this project but it is time
for an update.
This has been mostly a spare time project, and you know how life tends gets in
the way sometimes...
The work itself has been a bit of a "maze of twisty little passages, all
alike" with many potholes and obstacles, but progress has been made.
The video below tells the tale:
https://youtu.be/KwaNschJg6w
Synopsis:
A real PDP-11/70 boots RSTS/E V10.1 through it's unmodified RH70 controller
with the data coming from the Massbus emulator.
Operation is rock solid and so far have not been able to break it. It also
passes the ERHAE1 XXDP diagnostic without errors.
We now have a viable option for modern storage for Massbus systems.
Still to do is performance optimizations, hardening against some edge cases,
and a large amount of code cleanup.
I only have a PDP-11/70 to test with, but it *should* work with any Massbus
system. Adherence to the DEC Massbus Specification was strict and every
attempt made to make it behave as a proper Massbus device rather than just
coding things to make the RH70 happy.
I am kicking around the idea of putting together a blog chronicling the
various trials, tribulations and milestones encountered along the way if
anyone is interested in reading the gory details....
Cheers!
Jim