[Simh] Questions regarding future simulator development

[Christian Gauger-Cosgrove]

I can't really comment on the coding regarding adding more MASSBUS
channels, or the RS03/04 so I'm just going to skip that part.


On 11 April 2013 09:59, Bob Supnik <bsupnik at comcast.net> wrote:
> 3. The problem with "console while simulating" is that SimH (at least when I was developing it) is single -threaded. That said, there is a way to handle this within the existing framework:
>
> - Insist that the console always runs via a Telnet window.
> - Let the keyboard sampling "device" look for more than ^E; in fact, let it accumulate type-ins into a command buffer. Note that all editing (echo, delete, etc) would have to be explicitly emulated, because the keyboard window, at that point, is in raw mode.
> - When ENTER is recognized, see if the command verb is part of a small acceptable set of commands that are safe to run while the simulator is executing. As Tim Litt points out, ATTACH and DETACH should work, because this is no different, from the simulator's point of view, than ^E, attach/detach, CONTINUE. EXAMINE is probably safe. Not much else is.
>
> While it all sounds good in theory, I expect a whole bunch of things are going to break. Most notably, lots of SimH device service routines assume that if a device is attached at the start of the routine, it will be throughout and don't implement comprehensive error recovery further down.
>
Could a solution be used similar to the "remote console" that was an
option for the 11/70 be used? It's more thoroughly covered on Henk
Gooijen's site; in the console connection have it capture any example
of a control-P (or make it user settable), and provide a somewhat
limited environment to put simulator commands in (e.g. examine,
attach/detach, lock/write, and "deposit SR <x>" on machines with a
switch register).

Having it sitting "in line" with the console terminal means that you
can redirect it along with the console. Also, having it as a (user
settable) escape character, means that it keeps compatibility with
user software, though.


That's just my idea though, and I'd have no idea how to make it work.


Cheers,
Christian