The I/O
on a full blown system is where a modern system might have emulation
problems
This is exactly where simulation has been hung up for years. The mass storage
and terminal system is complex, with microcoded controllers for tape and disk
and dedicated front end processors for terminal/network I/O. KL10 simulation
is a cakewalk compared to this (and the KL10 was no small feat of programming).
I've dug up some additional information Olin Siebert didn't have, but there is
still a lot of internal Honeywell HW/SW documentation on the I/O that hasn't been
found.
This whole issue has been bounced around on the Multics mailing list and alt.os.multics
for years.