On Jul 24, 2016 8:58 AM, "Jerome H. Fine" <jhfined...@compsys.to> wrote: > > >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 with >> 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 about > 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