Booting up and LSI 11/23

From: Grant I Mitchell <gim_at_hitec-uk.com>
Date: Thu Sep 3 04:19:34 1998

Tim,

The drives are Diablo 30 drives, and the disks (there are several), are
marked
PDP-11 system disk, and PDP-11 Backup disk. The previous owner told me when
I
picked them up, that they should boot. Last night, I tried playing around
with
it again, and tried to access the disk status register (round about
17400(8) from
memory, but I'm at work just now and it was late last night, so my terrible
memory
can't be sure...). It seemed to contain 000000 (from typing _at_17400/). :(
Which
doesn't, as far as I can tell from the assorted docs, look to promising for
the state drive.

An other potential problem is that I believe a clock pulse was generated by
a
CAMAC crate attatched to it. I've got the crate, but cannot attatch it at
present
because it needs a 110V supply, and I don't have my 110V transformer just
now.

My house is a 240V only zone at the moment, or at least as long as these
machines stop tripping the surge detector!. I need to install a more
forgiving
fuse box.

Thanks for your help.

Grant

>>at $ prompt type in drive name
>>
>> $ DK0
>
>What sort of media are you actually trying to boot? Why do you think
>it's got a valid boot-block?
>
>>It now takes me back to the _at_ prompt.
>>Type in 0g
>>
>> _at_0g
>>
>>and I get 000002 back.
>>I'm assuming that the '2' I get back is an error of some sort. Can anyone
>>shed any light
>>on this one for me.
>
>Nope, it's not an error - it's the address the CPU stopped at. It's
>certainly the case that at address 0, there's a "HALT" instruction
>(i.e. the contents are zero.) This is very possibly because the boot
>block you read into location 0 was all zeroes - i.e. not a boot block
>at all.
Received on Thu Sep 03 1998 - 04:19:34 BST