RSX11M+ on SIMH - The Problem With RSX File Headers

Parent Category: How-to's Category: Getting RSX11M+ running on SIMH Written by Administrator

The baseline RSX distribution on trailing-edge also contains the distribution for DECnet, and Fortran 77 but has one small problem that is easiest to fix before you get too far. Even though the disk expands to ~160 MB it was formatted with only 3308 file headers. If you do a SYSGEN you will only have a few free file headers and thus be very limited on that system disk in the future. Each file requires a file header and the disk image that is available on the trailing-edge web site has a very small number of them for the size of the disk. The easiest way to fix this is to create 2 copies of the baseline disk, then boot the original disk, mount /foreign the other two disks and use BRU (RSX’s Backup & Restore Utility) to copy one of the copies over the other one while using BRU’s switches to add more file headers.

   So first on the linux system, make two copies of the baseline disk

#: cp rsx11mplus_4_6_bl87.dsk rsx11mpbl.dsk
#: cp rsx11mplus_4_6_bl87.dsk rsx11mpbl_mxf.dsk

   Next, create a Sim.ini file that attaches these disks to a RQ type disk. See below for an example sim.ini.

#: vim sim.ini
set console log=./console.log
set cpu 11/93, 4M
set cpu idle
set rq0 rd54
attach rq0 rsx11mplus_4_6_bl87.dsk
set rq1 rd54
attach rq1 rsx11mpbl.dsk
set rq2 rd54
attach rq2 rsx11mpbl_mxf.dsk
set dz lines=16
attach dz 10001

I assume at this point you have a copy of the PDP11 Simh, but if not it can be found at Now let’s boot the baseline RSX system with an 11/93 CPU.

#: ./pdp11
PDP-11 simulator V3.9-0
sim> do sim.ini
Logging to file "./console.log"
Disabling CR
Disabling RK
Disabling HK
Disabling TM
CLK, 60Hz, address=17777546-17777547, vector=100

Let’s verify that the disk volumes are attached properly:

sim> show rq
RQ, address=17772150-17772153*, no vector, 4 units
RQ0, 159MB, attached to rsx11mplus_4_6_bl87.dsk, write enabled, RD54
RQ1, 159MB, attached to rsx11mpbl.dsk, write enabled, RD54
RQ2, 159MB, attached to rsx11mpbl_mxf.dsk, write enabled, RD54

Now let’s boot RSX:

sim>boot rq0
RSX-11M-PLUS V4.6 BL87   2044.KW System:"RSXMPL"
>;                     PLEASE NOTE
>;     If you have not yet read the system release notes, please do so
>;     now before attempting to perform a SYSGEN or to utilize the new
>;     features of this system.
SET -- Inquire cannot determine terminal type
>; Please ignore any random characters that may have printed on your
>; terminal just now. They came from a SET /INQUIRE=TI: command.
>; Evidently your terminal does not recognize escape sequences.
>; This will not affect the running of this command file.
>* Please enter time and date (Default:01-JAN-2014 16:05) [S]:
>ACS SY:/BLKS=1024.
>CLI /INIT=DCL/CTRLC/DPR="<15><12>/$ /"
>@ <EOF>

Since we chose an 11/93 we only needed to hit return at the date/time entry prompt.

You now have a running RSX11M+ system. You may want to set the terminal type to a printing terminal to get a proper display of things like RMD (see appendix E) the remote memory display. You could work with this system except for the low number of free file headers.

DU0: has 172844. blocks free, 138456. blocks used out of 311300.
Largest contiguous space = 143720. blocks
402. file headers are free, 2906. headers used out of 3308.


Download this file (appendix_e__rmd_display.txt)Appendix E[RMD display]1 kB