24 Jul
2016
24 Jul
'16
8:06 a.m.
On Jul 24, 2016 8:58 AM, "Jerome H. Fine" <jhfinedp3k at compsys.to>
wrote:
with
about
On Wednesday, July 20th, 2016 at 18:02:44 - 0400,
william degnan wrote:
> Is there a minimum memory requirement for RT-11 v5? I was discussing Ray Fantini
about it today, unsure...anyone know if 16K will work (from
000000).
Bill
You need to be more specific! Starting with V05.00 of RT-11 in 1983,
there were a total of 17 versions released up to V05.07 in 1998, including
sub-versions V05.01B, V05.01C, and V05.04A to V05.04G of RT-11.
Up until V05.05 of RT-11, RT11SJ.SYS required the least memory which
was replaced with RT11SB.SYS for V05.06 and V05.07 of RT-11.
Attempts to boot from RT11SJ.SYS under V05.00 of RT-11 with 24K
bytes of memory were successful. Attempts to boot with 16K bytes of
memory were unsuccessful. An RK05 was used as the disk drive since
it is close to the smallest device driver. The answer to your question using 16K bytes of memory is NO for all versions of
RT-11 starting with
V05.00 or RT-11.
Attempts to boot from RT11SJ.SYS under V04.00 of RT-11 with 24K
bytes of memory were successful. Attempts to boot with 16K bytes of
memory were also successful. An RK05 was used as the disk drive. The
error message "Insufficient memory" is displayed, but some useful work
might be done with just 16K bytes of memory. However, you did not
ask if useful work being done was one of the criteria?
NOTE that I used the Ersatz-11 emulator to check the above details,
so there might be a difference with actual hardware.
If you have any more questions, please ask.
Jerome Fine
Thanks for the details. I had been trying to boot rt-11 v5.3 on a 16k core
11/40 using RL11 (rl02) and it did not work. The system was unable to
complete the initialization. CPU diagnostics passed, I could load BASIC
papertape. RL11 working correctly. In this context I posted my question.
After I posted my message here I loaded up simh and emulated an 11 with
32k. RT-11 v5.3 disk boots. When I re-built the system and reduced to
16k, I could not boot, bombed.
One thing to remember is 16KW in a pdp11 is not the same thing that simh
refers to when one sets the CPU to 16K. WWW do not all make this
distinction clearly. I get it, just making this comment for future readers
of this thread.
Bill