RSX11S

[Mattis Lind]

While archiving a bunch of old 8 inch disks I found disks that apparently
contain an old RSX11S system. I think it has been used in some kind of
railroad CTC system.

https://dl.dropboxusercontent.com/u/96935524/Datormusuem/PDP11RX01DISKS/DISK4.RAW

It is possible to boot this image in SimH (when setting CPU type to 11/03,
11/23 (F11), 11/34 or 11/73 (J11) )

I get this:

sim> b rx0
XDT: 18
XDT>g
RSX-11S V02 BL18


 DEVICE TT01: NOT IN CONFIGURATION
 DEVICE FT00: NOT IN CONFIGURATION
>a
MCR -- 1
>b
MCR -- 1
>ccc
MCR -- 1
>


So first there is a XDT> prompt. By pressing g or p it starts RSX11S. But
it seems to be possible to do other things. Commands like "s" and "l" do
stuff "x" causes:

XDT>x

SYSTEM CRASH AT LOCATION 025276

REGISTERS

 R0=000000 R1=177170 R2=003403 R3=157000

 R4=012422 R5=000002 SP=157004 PS=000340

SYSTEM STACK DUMP

 LOCATION CONTENTS

  157004   157150

HALT instruction, PC: 000572 (MOVB #15,R2)
sim>

I understand that RSX11S is a scaled down version of RSX11M. An embedded
RTOS of that day. But what kind of commands are possible at the XDT and
MCR(?) prompts. I am a little bit curious to understand more about the
system that it has been running.


/Mattis