Here's more info on the PDP boot problem. Since my girlfriend knows more
about it than I do, I'll let her explain :).
From: Joan Sarah Touzet [mailto:joant@Cadence.COM]
Sent: Friday, July 31, 1998 9:27 AM
Subject: Forward for your mailing list
I'm sorry for my boyfriend's post lacking details on my PDP
not familiar with these systems, and was hoping there was a simple
answer (and a simple configuration!) for dead PDP-11/23s.
Unfortunately, no such thing ever exists... ;) (So I'm the QBus
person, and he's the S-100 bus person. You can imagine the fights we
have over dinner.)
Anyway, all joking aside, this is a PDP-11/23 system. It's installed
in a Charles River Data Systems backplane & enclosure, which
8" drives which I believe are double sided. (I'll open the case this
weekend to confirm, and to CLEAN!) The system has been stripped down
to only the essential modules: a KDF-11A (PDP-11/23 CPU with FPU
installed, M8186), an MXV-11 multifunction serial/32K memory card with
local refresh (M8047-CA), and a Charles River Data Systems
controller board. I currently have the backplane configured as such:
With no documentation on the FC202, it's hard to know whether it is
trying to share an interrupt with the M8047, but I've been told it's a
dropin replacement for the MXV21, so I've placed it as such. FYI, the
backplane is quad high, with 8 rows of slots.
I have been trying to boot RT-11SJ v5 from drive 0 using the RX02
single and double density bootloaders, as well as the RX01 bootloader
on the off-chance that these are single-sided drives. One of two
1) After RS/340, R7/1000, P the run light comes on, drive 0's busy
light comes on
(and it sounds like it seeks to Track 0) but the system hangs
there. In this
case, the RUN light stays lit until I send BREAK or front-panel
toggle from ENBL
to HLT. This happens in less than 1/2 a second. I don't hear
seeking from the drive.
2) After RS/340, R7/1000, P the run light comes on momentarily,
drive 0's busy
light comes on (and seeks to Track 0), the run light
extinguishes, and I'm
dumped to ODT somewhere around 1104. (The address can vary.)
This happens in
less than 1/2 a second.
I am unconvinced that the drive is actually returning a media error
this quickly. I've also let the system sit in state 1 for the
approximate time I remember it took these systems to boot (30
It's been 18 years...) but no kumquat.
I've also entered some of the diagnostic programs I've found in the
Microcomputer & Memories books I've got floating around (1981, 1982
editions). Most of the tests pass. The ones that don't are
the "continuous stream of ASCII characters to the console prompt" and
the "press a key, create an interrupt, and halt the program" ones.
After trying multiple CPU and MXV11-CA modules, and still seeing the
same erroneous behavior, I'm beginning to suspect that those programs
don't quite work as indicated. I haven't gathered up the gumption to
bother debugging them by hand yet.
Oh, and in case you're wondering, I have the CPU module jumpered to
power-on into ODT, and the MXV11-A module is pretty much at
defaults. Some of the MXV11-As that I have, have boot PROMs installed
in them, and so the PROM address jumpers may be different than those
listed as factory defaults, but everything else is "by the book."
One final note -- this system and enclosure were working a few years
ago in an expanded configuration (with 3rd party memory add-on modules
I've since removed, as well as a bunch of Analog Devices-powered A/D
boards, and an RGB Peritek video board) so I'm pretty sure
that the bus
is configured for a /23 already, instead of for an LSI/2 or something.
Any ideas? My current plans for the weekend involve taking the
enclosure apart and cleaning the drives within an inch of their lives,
then trying to boot again using the RX02 bootloaders. I'm starting to
run out of ideas.
-Joan Touzet (go ahead and reply to the list, I can read it just fine
through the archives page :P )
- Joan Sarah Touzet | So grey is not the color I
- joant(a)cadence.com | On someone who's so often
touched by grace -
But always she's the spectre of
- I still love OS/2. | I first endured, then faded,
then embraced... -