While most of Y'all were at the VCF, I decided to spend my time in similar
activities and dusted off two projects I've been tripping over for weeks:
my two ASR-33's (more on them in another posting) and a Heathkit H-11 that
I rescued from a former employer a few years ago.
The H-11 was pretty goobered up from the previous owner. He soldered wires
right on the DLV11-J connectors, for example. He also cobbled up his own
CD slots for an RLV11 by extending the case out another 4 inches and wrapping
two pairs of Heathkit Q-bus sockets together. It was gross. I have the case
back together (except for the top, which he lost) and have been working on
the cards.
I discovered in my piles of CPUs that I have two M8189 "PDP-11/23plus" boards
with different ROM revisions. One has the numbers "SG8335 339E2" and
"SG8335 340E2" on them and behaves like the description in the handbook. The
other board is populated with "LM8451 183E4" and "LM8451 184E4" and comes up
with a much more interesting banner. It claims to be Rev 0.9 of a ROM set
for the 11/23plus, and after verbosely testing memory, tries to boot DU3.
You have the option of retesting memory, dumping a memory and I/O map or of
booting from several devices including tape, network and several flavors of
disk. This brings me to my next problem...
The Heathkit floppy controller is labelled "H27" on the white handle with a
silk-screened part number of 85-2183-1. If I put it next in the grant chain,
the 11/23plus hangs. If I put it at the end of the bus, the 11/23plus tests
and lets me try to boot from it. I have the cover off the floppy case and I
can see the heads load and boot. They drop to track 0, move around, read in
a few tracks, then unload and the CPU never prints out another thing. I
suspect that something to do with DMA or interrupts is hanging the CPU once
RT-11 loads into memory. I did pull all the chips (100% socketed) and test
them one at a time. Some failed on the first go, but passed after wiggling,
telling me that there is some oxidation on the leads. I pulled and reseated
everything and will try this thing again when I get back out to where the
H-11 is.
In the meantime, I am wondering if the H-11 floppy box is pin compatible with
an RXV11. I happen to have one here, but I don't want to fry something if
they are not compatible. BTW, there are three jumpers on the H27 - E1, E2
and E3. The card passed into my hands with E1 and E2 strapped, but not E3.
Finally, eventually, I want to get original stuff back into this box. I have
the DLV11 console board that came with this, I'm just not using it. In
addition
to the H27 floppy card, I have a Heathkit lineprinter card (unassembled) and
a wad of Q-bus CPUs from the LSI-11 up to the 11/23plus (nothing newer,
unfortunately). So the question is, what "belongs" in this box. Did it come
with an 11/03 "LSI-11" CPU? An 11/23 F-11 board? What did the H-11 use
for boot roms? A BDV-11? An MXV-11? A Heathkit board?
Thanks,
-ethan
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Infinet has been sold. The domain is going away in February.
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Received on Mon Oct 04 1999 - 00:37:28 BST