28 Sep
2020
28 Sep
'20
3:07 a.m.
So that confuses Q22 memory. If one tries to use one
with an LSI-11,
the machine is totally dead - not even ODT.
Oh, that's another LSI-11 'feature' (only discovered after someone sent in
a
help request on CCalk for a dead LSI-11): if there's no working memory at 0,
ODT won't start/run. So if the Q22 memory is confused, the whole machine is dead.
Noel
28 Sep
28 Sep
3:12 a.m.
New subject: Fwd: Choice of Unix for 11/03 and 11/23+ Systems
On Sun, Sep 27, 2020, 3:08 PM Noel Chiappa <jnc(a)mercury.lcs.mit.edu> wrote:
Maybe a bit of electrical tape over the fingers on the 256KB board would
keep them isolated from these signals? That would help determine if it is
just floating pins, or that the LSI-11 used these pins for other reasons?
Warner
So that
confuses Q22 memory. If one tries to use one with an LSI-11,
the machine is totally dead - not even ODT.
Oh, that's another LSI-11 'feature' (only discovered after someone sent
in
a
help request on CCalk for a dead LSI-11): if there's no working memory at
0,
ODT won't start/run. So if the Q22 memory is confused, the whole machine
is dead.
6:22 a.m.
New subject: Fwd: Choice of Unix for 11/03 and 11/23+ Systems
On 27/09/2020 22:12, Warner Losh wrote:
Maybe a bit of electrical tape over the fingers on the
256KB board would
keep them isolated from these signals? That would help determine if it
is just floating pins, or that the LSI-11 used these pins for other reasons?
No need for tape or any other test. The pin assignments for both the
original LSI11 bus, as used in the 11/03, and the Q22 bus used in later
machines, are well documented. The 16-bit pinouts are listed in the
1976 edition of the Microcomputer Handbook, the 18-bit in the 1980
edition, and there's a comparison table with Q22 in the 1982
Microcomuters and Memories handbook. There are more differences than
the BDAL18-21 lines and there are even differences between the KD11-F
and KD11-HA.
The SRUNL signal that was mentioned isn't likely to cause a problem;
it's on both AF1 and AH1 in an 11/23 and a KD11-HA, but only on AF1 on a
KD11-F, and I'm not sure it's bussed anyway in most backplanes.
BDAL18L is on BC1, and that's an internal clock signal on a KD11-HA.
BDAL19-21 are on BD1-BF1 and they're connected to MICROM signals in the
KD11-HA. None of them are connected to anything on a KD11-F.
--
Pete
Pete Turnbull
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Warner Losh