PDP-11/24 bootup w/9312

From: Daniel T. Burrows <dburrows_at_netpath.net>
Date: Tue Dec 15 20:19:13 1998

>>S1= ON Boot to ODT 165xxx
>>S1=off Boot selected device 173xxx
>>s2=off for 11/24 use
>>s3 through s10 are starting add.
>
>S1 is set so that 1 thru 8 is 'OFF' and 9 + 10 are 'ON' as I found it.

9+10 means boot 173006 diagnose on (sizes memory etc.)
> -- 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.


correction 01000000 = 256k bytes /128k words sorry old age I guess

>Then Tim Shoppa replied:
>
>>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.
>
>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
9302.
>
>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 ("_at_01000000") and a few
>flickers of the "Ready" light on the RL02.
Should start booting shortly (less than 30 sec.after mem size displayed)
I waited at least five minutes
>or more several times. After thinking I've waited long enough to grow old
>waiting, I Halt the processor and "_at_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.)


I don't know about RT - all my experience is with RSX11M+ but I would guess
that it is not seeing the boot sectors. IE: try another platter. Before
inserting another disk check / clean the heads, check the old platter for
those nasty rings.

Dan
>
Received on Tue Dec 15 1998 - 20:19:13 GMT