[Simh] pdp-11 id command quirk
Jon Elson
elson at pico-systems.com
Wed Jun 15 11:47:37 EDT 2011
Hello,
I want to use the pdp-11 sim of simh to teach my kids some
machine-language programming.
I have it compiled and running on a Linux system. When using
interactive deposit
in the PDP-11 simulator, it increments by single byte addresses, so you
get :
PDP-11 simulator V3.8-1
sim> id 1000-1004
1000: 1234
1001: 2345
1002: 3456
1003: 4567
1004: 5670
sim> e 1000-1004
1000: 002345
1002: 004567
1004: 005670
so, you see that only every other deposit address actually wrote to
memory, and the examine
command properly increments by words. If there is a by-word switch to
the id command, I couldn't
figure it out from the source or help text. (I do see that id -c writes
2 ASCII characters to even addresses,
and writing assembler mnemonics also works, but numeric values increment
by one.)
I tried the same thing on the vax780 sim, and it works fine, depositing
32-bit values on longword
addresses, and then examining them just fine.
If there is an option switch that makes it work correctly, I was unable
to find that by inspecting the source
or the documentation, or searching the simh archives.
Thanks,
Jon
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