SIMH question

Noel Chiappa jnc at
Wed Apr 24 10:05:08 CDT 2019

    > From: Glen Slick

    > when I wanted to assemble some code with the RT-11 assembler but wanted
    > to edit the source code elsewhere and then transfer the code into a
    > SIMH disk image.

Someone should write the SIMH equivalent of Ersatz-11's 'DOS device' (which
allows the -11 access to the file system on the host - and also the ability
to send arbitrary commands to the emulator).

I find it mind-bogglingly useful for going round the edit-compile loop, while
using a good editor (Epsilon for me) on the host OS. Having written a Unix
driver for the device, I have a sack of Unix commands that use it, e.g. to
retrieve the file foo.c from the host, I just say 'hrd foo.c' to the PDP-11
Unix's shell, and it's there.

Super-painless, and does't add any noticeable amount of time/work to going
around the loop. I don't need to give the full file name since there's also
'hcd <dir>'. To change the switch register contents, 'sc <value>'. Etc, etc.

How all you SIMH users manage without it is beyond me. Luckily I only need
-11 emulation, so I don't have to put up with life without it - and would
refuse to.

If anyone is seriously interested in adding it to SIMH, there's an -11 device
spec available; I strongly suggest using the same spec; then for Unix, at
least, all the -11 code (driver, user commands) is already done.


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