RT11 V4 on 11/2 halts at 1002 at boot time

[leegleason]

I've been playing around with some old QBUS parts here, with an eye to assembling a small desktop system. I loaded a KD11-HA (LSI-11/2) and an M8047-CA (MXV11-AC) into a BA-11VA (4 slot "leprechaun box").

Using a TU58 emulator, this will successfully boot any of the several XXDP TU58 images I have (via 173000G).

Testing with ODT shows the MXV11 RAM is present and goes from 0 to 32K. I figure the boot roms are OK and mapped at the right place, because it boots XXDP fine.

I wanted to see if it could run RT-11. I created a TU58 image of RT11 V4 (it's what I had laying around), using SIMH. This image will boot and run fine in SIMH, with SIMH set to CPU 11/03 and 32KB. But, when I try to boot it into the 11/2 system, it loads a few blocks, and then halts at 1002 - console just says 01002.

Any suggestions as to what could be tripping me up here?

--
Lee K. Gleason N5ZMR
Control-G Consultants
lee.gleason@comcast.net

 

[wa2flq]

32 KB of ram may not be enough to run RT11 V4 depending on its configuration. Is it an SJ or FB monitor? RT11 was supported on 32KB through V5, but it needs to be a minimum system.

The hardware seen in on the 11/2 by RT11 may differ from SIMH. This may result in different ram requirements as the monitor loads.