S1 is set so that 1 thru 8 is 'OFF' and 9 + 10 are 'ON' as I found it.

-- snip -- >I am surprised you have the M9312 in that machine since you have 1 meg of >memory. Normally you would put the boot rom on the KT24 (M7134) and use >just a M9302 terminator.

Then Tim Shoppa replied: Normally, yes, that's what you'd do. But it is possible to use more than 256 K without the KT24 memory map/bootstrap module, assuming your OS never tries to do I/O to memory past 256 K. For example, RT-11 SJ, where the extra memory is used as a virtual (VM:) disk drive. Well, this machine has just a single M7891-DH with 128 KW of MOS RAM. Tim, I assume you meant 256K *bytes*? :) There is no KT24 in this machine. It's kinda scrawny featurewise for such a machine. Not even a DD11-DK expansion backplane is installed. Has two RL02's in the cabinet. Came out of Case Western Reserve university so it could have been hacked to make a 'smaller' system for instructional use or just for lab use. Still has the UDA50 boardset for SDI disks but no SDI "DU" boot ROM (767A9). Who knows <shrug> . . . Anyway, the lack of a KT24 explains why a 9312 was used instead of the

BTW: after flicking the boot switch, about how many minutes should it take to do the prelim. tests before any evident booting action takes place? I just see the # of bytes of memory displayed ("@01000000") and a few flickers of the "Ready" light on the RL02.

or more several times. After thinking I've waited long enough to grow old waiting, I Halt the processor and "@1013" is written to the display. Could there be a hang? (Got simple info out of my RT-11 5.1 manuals on how to boot an 11/24 just this AM. Stumbled upon it, actually.)