I have three AlphaServer 2100 systems in storage in the UK
(Oxfordshire). The storage, however, is due to be demolished (soon, but
no fixed date).
I won't have room to store these three systems, so if anyone would be
interested in offering them a home, then please get in touch!
I can probably get some pictures in the next day or two.
These systems were SMP Alphas and could sport as many as 4 CPUs. I'm not
sure of the configuration of these systems but I can probably find that
They have not been run since ~2003 so they may be in need of some TLC.
OTOH they are not rusted to death so you have a chance of getting them
back to life.
Just so you know what you might be dealing with these systems are about:
700mm H x 430mm W x 810mm L.
I can't find the weight in any of my references right now but they are
very heavy. Three people can move them up a slight slope with some
effort but you would not successfully lift it into a car (assuming that
it would fit). I'm planning to dismantle them to move them (i.e. remove
PSU/PSUs etc. until they are light enough to move). A tail-lift would
probably be the sane way to go (and is, indeed, how they got to their
I'm hoping that someone can step forward and offer one or more of these
machines a new home. Please contact me off-list (once you're sure you
understand what you are getting into :-)).
antonio at acarlini.com
The recent discussion on BSC protocol prompted me to dig out my Microvax 3100
with DSH32 synchronous serial interface. It had been idle in storage for
several years and it wouldn't power up, only giving a brief flash on the
diagnostic LEDs and a quick twitch of the fans. There was a slight smell, like
the stale air that comes out of a deflating tyre.
I took out the H7821 power supply and found that five identical brown 1800uF 25V
electrolytic capacitors on the output side had leaked.
The SCSI disk enclosure where the machine's system disk lives required several
power cycles to get it to run at all and it died as soon as the disk tried to
spin up. It turned out to also contain a H7821 power supply which had a
similar issue with the same five brown capacitors, although not as extensive
as in the main unit.
I found a second disk enclosure which had seen little use and grabbed the power
supply out of that to put in the MicroVAX. It worked well enough to test with
but there was a ring of goo around the bottom of one of the brown capacitors
which was worst affected in the other units. Time to order a batch of
replacement capacitors and figure out what else has been damaged. While it is
not the worst I have seen, access to these power supplies for repairs is quite
difficult and it is really difficult to debug them safely while they are
running with the cover off :-(
If anyone has anything with H7821 power supplies in them, I suggest checking
on these capacitors. If anything with these power supplies is in storage, I
suggest ensuring it is stored the normal way up as this should limit the
ability of the goo to escape and spread around the power supply.
And there I was thought I was being safe enough by removing the nicad battery
packs some years ago...
> From: Mattis Lind
> Thanks Noel for sorting this out.
Eh, de nada. But thank you.
>> I wonder if the ucode in the two versions is identical? The uROM chip
>> numbers should give it, (if they are the same on both versions, albeit
>> in different locations on the board), but I have yet to check. Does
>> anyone happen to know?
OK, so the situation here is pretty complicated. To start with / make things
worse, that CPU uses lots of PROMs. Lots and lots and lots and lots of PROMs.
For the data paths board (M7260), both major versions appear to contain the
same PROMs (going by the DEC part numbers), but the chip location (Exx)
numbers are all different.
For the control board (M7261), the C, E ('early' version) and F ('late'
version) etch revisions each contain mostly the same PROMs, but apparently
with slight differences between the sets of PROMs in each (as reflected in
different DEC part numbers). For details see:
to which I have just added all the gory details.
As to getting the contents of all of them dumped in machine-readable form -
>> on the earlier version (prints for that version are in the GT40 prints
It turns out that I have hard-copy prints for the "C" etch revision of the
M7261, which do not yet appear to be online; the GT40 prints have the "E"
I will scan the pages for that revision of the board, and put them up 'soon'.
(I'm not doing the whole print set, it's about 1" thick, and most of them are
for other things anyway, like MM11-L memory, etc.)
In item https://www.ebay.com/itm/265045229011 I am curious as to whether the
gold islands on the top-side are functional test-points giving electrical
access to the underside pins? Was there a clip designed to attach to the
top-side of these chips for use in circuit analysis? Was this design unique
to Russian manufacture (I don't recall ever seeing this design previously)?
> From: Paul Koning
> There's a good reason why the big disks on many DEC machines were Massbus
> devices until MSCP arrived. It's quite clear on Unibus PDP-11s, which
> needed Massbus both for speed and for a cleaner answer to more-than-18
> bit addressing.
I follow the first sentence, but I'm confused by the second, especially "a
cleaner answer to more-than-18 bit addressing". The UNIBUS MASSBUS
controller/adapter, the RH11, only has 18-bit addressing on the main memory
side. It does have more than 18-bit addressing on the device side, but so does
the RP11 (sort of). Are you thinking of the RH70? That does have access to
more than 2^18 bytes of main memory, but that's because it connects to the
-11/70 memory bus (as well as the UNIBUS, which is only used for control, not
Similar questions about the speed point; passing data through an RH11 doesn't
increase the speed of the UNIBUS? Yes, the RH70 is faster, but that's because
of its connection to the -11/70 memory bus.
I realize these are uncommon; curious if anyone has a spare pair somewhere
(hey, that rhymes.) I'd like to be able to pull out the CPU on my 11/70
without worrying about the whole thing tipping over and crushing people I
care about. It's the little things, really...
I picked this up a number of years ago for reasons that entirely escape
me. It's certainly neat, but I don't see myself ever actually using it and
it's large and heavy.
Mine appears to have a DEC-style interface but I'm unsure what it talks to
on the DEC side of things.
I can take pictures if there's interest, but it's fairly nondescript, just
a large white box with rack-mount ears and a small panel with some switches
It's in the Seattle area if anyone wants it, and it's free! Shipping is...
not something I really want to think about right now.
> From: Steven Malikoff
> I have yet to machine the bolt head tapers to the originals but lost
> the photo of one that was posted here some time ago.
By "bolt head tapers", do you mean the special bolts with countersunk heads,
or the countersunk holes in the extension feet? Whichever it was, I can
provide photos and/or measurements, as needed.
In case this link only made it to discord, I'm (re-?)posting here.
Cindy has been extremely helpful and generous and giving of her time to all
in this hobby. It is a very worthy cause.
Not too much more to hit their goal. Lets see if we can put them over, I'm
pretty sure most of us have benefited from her efforts.
Cindy, a few things have changed on my end with retirement, but I may be
able to get that website back online for you. Please reach out to me
directly and I'll check.