I have a BA23 chassis that was used to hold 3 DSSI disks. There was a
different backplane with the load resistors instead of QBUS slots. There was
also a large capacitor bank installed along side the DSSI disk in the place
of the QBUS slots. I can dig around next week when I go back home if you
still need the resistor sizes DEC used.
> From: Joe Zatarski joezatarski at gmail.com
> The posts you mentioned were sent to cctech. .. that list is
> moderated .. You'll notice these posts are now in both archives.
Ah, that could be it. I thought I'd found them in the Subject: thread
archive at the same time they weren't in the other, but maybe my memory is
> From: Eric Christopherson
> the reply to the message headed "No subject" .. actually seems to
> have a blank subject, as a result of which it doesn't seem to be
> possible to even view it (since there's no link to click)!
Which is how I discovered those messages which weren't (yet) in the
archive; I took the URL for the previous message, edited it to point to
the next message, and discovered the 'missing' ones. (Apparently the
list software makes messages available via the Web interface before
they've been approved and added to the archive.)
> John H. Reinhardt
> And now I know why your posts always break the threading in
Hey,I don't want my emailbox clogged up with this stuff! :-)
It's a VAXstation II/GPX. I'm trying to install VMS 5.5 (from CD if it matters; there is a CMD CQD-200 or -220 as the only storage controller) and routinely getting machine check exceptions.
Standalone backup always boots. Sometimes I get an exception the moment I hit <enter> on a restore; sometimes in the middle of the restore, sometimes it runs to successful completion.
VMS never boots. Sometimes I get as far as the date prompt (I took out the battery), sometimes it gets a little farther, frequently it's before anything appears on the console at all.
The exceptions booting VMS occur the same if I attach another disk with VMS 5.5 already installed; if I replace the KA630 and M7609 with a KA655 and M7622, it all seems to run fine.
The KA630 power-on diagnostics all pass, but... it smells like a memory fault to me. What are the odds there could be a memory fault that isn't caught by the diags?
until further notice
> From: Bob Smith
> there have been refs to another more modern unit, based on LSI[-]11
> or later chip set
I've never heard of that, and I wonder if DEC would really have released
a new product with the same name as an old one (the two PDP-11/10's
are different, as I'm not sure many of the first ones were sold, but
a ton of -11/15's were).
> I wonder if it is one of those or the orig.
This one is one of the -11/20 type ones.
> From: Paul Koning
> I only ever heard of an 11/15 as the 11/20 relabeled for OEM
According to the "pdp11/15/20/r20 processor handbook", 1972 edition (i.e.
the second edition of the -11/20 proc handbook), the /15 has (table on pg.
2) a "KC11" processor, which seems to be a KA11 with only a single
interrupt request line. (Maybe it has a replacement card for the M824,
with only a single interrupt line wired up?)
There's a 'KF11-A' option which upgrades it to multi-line (pg. 4), for
which there claims to be a manual (DEC-11-HKFA-D), but there are none
online, but from other traces online it does seem that some people had
to get and install it. So maybe the stuff in the proc manual isn't
just marketing wibble.
That same manual claims that power-fail restart was standard in the
KA11; it was an option for the KC11, the KP11-A.
> From: Ray Jewhurst
> I would really like to get my own classic computer but I don't know
> where to begin.
Two questions you need to sort out in your mind, to decide, are i) do you
want something with a bit-mapped video screen, or are you happy with ASCII
serial line only, and ii) what are you prepared to do for mass storage.
E.g. if you really want video, you're probably looking at something like a
VAXStation or so; if ASCII will do you, a QBUS PDP-11 might be a good
start, as with patience eBay can yield a cheap chassis, CPU etc (although
in the last year or so the really cheap stuff seems to have dried up,
At 03:30 PM 17/06/2019 +0100, Ronan Scaife wrote:
> Dear All,
> I am particularly interested to make contact with Ireland-based
> classic computer collectors or users.
on 18 June 2019, Guy Dunphy wrote:
> Message: 8 Date: Tue, 18 Jun 2019 09:34:11 +1000 From: Guy Dunphy
> <guykd at optusnet.com.au> To: ronan.scaife at dcu.ie, "General Discussion:
> On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Re:
> irish cctech subscribers Message-ID:
> <184.108.40.206.20190618093411.011eaad8 at mail.optusnet.com.au> Content-Type:
> text/plain; charset="us-ascii" Hi Ronan, I know you meant 'in
> Ireland.' But I can't resist: I'm of Irish ancestry, though born and
> residing in Sydney Australia. Also "My particular interest is in DEC
> pdp-8 and pdp11 machines." Never thought I'd actually have any, until
> unexpected events of 2018 and ongoing. Now so far I have two PDP-8/S
> to restore ( http://everist.org/NobLog/20181104_PDP-8S.htm ) and two
> PDP-11: Rack 1: PDP 11/44 and one RLO2 diskpack drive. Rack 2: PDP
> 11/34, two RLO2 diskpack drives, and one RK05 disk pack drive. Seems
> to be a complete, intact system. I have the side panels, various
> blanking panels, and assorted documentation. Still making arrangements
> for a long-term space to set them up and work on them. Regards, Guy
>> My particular interest is in DEC pdp-8 and pdp11 machines.
good to hear from you!
My interest stems from the generosity of DEC Galway, Ireland, who helped
start my (DSP, speech) research career
in the early 1980s with a generous donation of 2x 11/34s with RL02 and
I also have a MINC (laboratory instrumented 11/23) from Trinity College
Quite recently, we acquired a pdp8/e (made in Galway) with RK05 and PC04
>from Dundalk Institute of Technology.
I haven't dared to power this up, but a few of my students have worked
on a replica pdp8/e front panel patched
into a simh emulation on a PC.
I look forward to reading your blog.
My medium term plan is to interest the National Museum or equivalent in
a section on (especially Irish-made)
technology, so the email was primarily addressed to people on the island
of Ireland. However, most of what I
have learned over the years has been from guys around the world like you
who are so generous with their
*S?anadh R?omhphoist/Email Disclaimer*
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I'm in the process of restoring an Intel 310 system. I had it working to
the point where it was trying to boot - when the 88/45 processor
began to fail intermittently and then solidly. My debugging seems to
indicate that the problem is in a PLD - which is a serious bummer.
I have preserved the ROMS (which have built-in diagnostics/debugging
and boot capability for both floppy and Winchester hard disks) as files.
I will make these ROM files available to Al for posting on bitsavers.
If someone on this list has an Intel 88/45 (or Intel 310) who would be
willing to part with it, please contact me off list. I can to either do
a trade or cash purchase...
Bickley Consulting West Inc.
"Black holes are where God is dividing by zero"