Help installing HP 2000 contributed library in simh

J. David Bryan jdbryan at
Mon Apr 6 22:59:52 CDT 2020

On Monday, April 6, 2020 at 20:39, David Williams via cctalk wrote:

> The problem I'm having is to load it I have to:
> [...] 
> 2) Select the S-register and clear the display. Set bits 15 and 0. Set 
> bits 11 through 6 to the low number (high priority) octal select code of
> the magnetic tape device controller.
>   - Bit more of an issue for me as I'm not sure what value to enter for 
> the tape device.

The included "" file indicates that the tape interface is 
assigned to select codes 16 and 17.  So the command you want is:

  DEPOSIT S 101601

> 3) Select the A-register and clear the display. Set bit 0. Press STORE 
> and IBL. The contents of the magnetic tape loader ROM are loaded into 
> memory.
>   - Here it stops. The doc says to use the "LOAD CPU" command to simulate
> pressing the IBL button but when I do I just get "Command not allowed".

The LOAD CPU command is not allowed unless the CPU is configured as a 
21MX-series machine.  By default (meaning unless you've changed it since 
starting the simulator), it is configured as a 2116, which does not have 
loader ROMs.  So doing this after setting the S-register would work:

  DEPOSIT A 000001

However, if the CPU isn't configured for Access, then probably the I/O 
devices aren't configured for Access as well.  The initial SIMH startup 
settings have to be changed to rearrange things to where Access expects 
them to be.

The simplest way to set up the proper configuration and then load the 
Master Control Program is to modify the existing "tsb-reload.sim" file.  
First, copy it to a new file named "tsb-convert.sim".  Then edit the latter 
by locating the line that says:

  go until "LOAD WHICH MODULE?  "  ; reply "%DISC%\r"

Delete this line and all of the remaining lines in the file.  Then append 
the command:

  go the end, so that the last two lines of the file read:

  go until "2754? "                ; reply "YES\r"

Save the file and then run it:

  hp2100 tsb-convert

The script will start up the IOP (I don't know if it's necessary in this 
case, but it's harmless) and then print:

  Waiting for the IOP to complete its initialization...

  Programmed halt, T: 102077 (HLT 77), P: 77756 (ALF,ALF)

  2754? YES

...on the system console.  Enter CONVERT, and then follow the remaining 
instructions in the sysop manual.  Note that the default uses an HP 7905 
disc drive for the system disc, so the question:

  DISC-0 A 7905 OR A 7920?

...should be answered YES.

                                      -- Dave

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