+1-410-734-6804
New hobby thing. ;)
Wildcat! 4 running on it, stock out of box config. If you don't see all the
menus except for help and send to sysop, wait till I validate users. When I
get back home i'll set it to give non-validated users more permissions,
though.
--
Gary G. Sparkes Jr.
KB3HAG
Can anyone help me to locate an old IBM 026 printing keypunch for a project on which I am working?I was an IBM Field Engineer many years ago and I used to service lots of Unit Record equipment at that time.Any help in locating a machine would be greatly appreciated.Thank you.
AlEx-IBM Field Engineer
> From: Holm Tiffe
> Anyway, thanks for the schematics
Eh, de nada.
> I have the board running again. The fix was simple, the xtal was bad.
You're lucky it was something so simple! (Although we've seen this kind
of thing before - I had that 11/23 with a bad crystal.)
I've got three dead 11/73 boards (from someone else), but none of them are
that easy. Different symptoms on all three, but I suspect the State Sequencer
gate array on all three. On one, at least, the ILOE latch control signal from
that gate array is sitting at 2V (which I seem to recall is characteristic of
a TTL input that's not being driven).
Maybe it's just some corrosion, and re-seating the gate array (if I can work
out how to unseat it - don't have the extraction tool) will fix it.
Otherwise, I'm SOL. At least the J11 there are spares for - that gate array
is surely umobtainium.
Noel
Bit of a tricky one to google this, so thought I'd consult the list -
does anyone know of a documented project that replaced the internals of
a BBC Model B with a Raspberry Pi (or MiniITX PC) interfacing with
keyboard etc. to bring modern internals with a traditional interface?
I don't even know if there is a word for these kind of projects?
Thanks, Mark.
So I've mentioned how I've seen this wierd behaviour where QBUS memory boards
that hadn't been used in a long time didn't work when first plugged in, but
started working later.
I just had something even weirder happen, and am curious if anyone has an
plausible explanations.
So I had a dead M8044 (MSV11-D), symptom was that you could write -1 to any
location, it read back as 0. Quite repeatable, I can power cycle the machine,
take the card in and out, etc, etc.
So I throw it on an extender, and start chasing. I have a two instruction
loop (write location 0, loop), and I'm watching the data going into the
memory chips on the card, and it all looks good. So I add a third instruction
(read location 0, after the write), and continue chasing.
Data looks good coming out of the chips; then it goes to an octal latch. So I
look at the latch enable, and that doesn't look so hot - just a tiny little
ugly spike. So I look at the source of that, and it's a D flop. So I look at
the D flop's clock input, and it's also a nasty little spike. So that comes
>from the output of a triple-AND, and so I start looking at the inputs of the
3-AND. And when I put my 'scope lead on the second input... the memory
suddenly starts working!
Well, I could see that - the added resistance or capacitance or whatever of
the probe might have had some effect on a circuit that was right on the edge.
But here's where the ghost enters the machine.
I pull the 'scope probe ..... and the memory keeps working!
I can power cycle the machine, leave it off for 15 minutes, power it back on
- and the memory still works fine!
Does anyone have _any_ idea WTF is going on here?!?!
I feel like I'm in some sort of AI koan...
Noel
Several people asked, here's the scoop:
The common proms for HP 21MX M/E/F are 1K, 4K, and 8K.
1K are used for either loader roms on the cpu board or microcode on the FAB
4K are used for microcode on the FAB or FEM
8K are used for microcode on the FEM
The manuals you'll want to print and keep handy:
HP 12992 Loader Roms Installation Manual, 12992-90001 (April '86)
HP 1000 M/E/F-series Firmware Installation and Reference Manual, 12791-90001
(September, '83)
I believe these are both on bitsavers. They are "must have" manuals.
These are all bipolar proms, and most modern prom programmers will not be
able to program them. I use a Data I/O 29B (with Unipak 2B), and it can
program all these parts. Those programmers appear on ebay from time to time
at around roughly $400.
The blank proms are not terribly easy to find these days. Ebay has them
occasionally, but your best bet is sites that cater to arcade machine
repair.
Here's a non-exhaustive but useful list of compatible parts for each:
1K parts
MMI 6301
Harris 7611
Signetics N82S129
National 74S287
TI 24S10
AMD 27S21
Fujitsu 7114 (possibly 7052 as well, need to verify that)
4K parts
Signetics N82S141
Harris 7641
MMI 6341
8K parts
Signetics N82S181
Harris 7681
MMI 6381
Anyone here get the Control Data 160 (Ebay 252070822992)? I must admit
time, money, and space aside I would love to have had this one! (I have
the manuals at least)
--
Bill
vintagecomputer.net
> There are a number of things like that (e.g. the H786 power supply for
> the BA11-N; [print sets] not available separately [online], but in the
> 11/23 FMPS [online], if you know to look there): we ought to produce
> some sort of registry, to collect such information in one place.
So I have started such a registry.
http://ana-3.lcs.mit.edu/~jnc/tech/FMPSOnline.html
The concept is that eventually search engines will index that page, so people
looking for, say, '"BA11-N" prints' will wind up there, and that page will
tell them where to go.
I went through a number of PDP-11 print sets which are online (11/05S, 11/23,
11/34, etc) to compile the initial list, but it's just a start. I will add
others as I come across them; and if any knows of, or finds, any others (i.e.
print sets which _are_ online, but do not show up when looked for in common
search engines such as Google), please let me know, and I will add them.
> I also found prints for the MF11-U, MF11-W, and MM11-Y; none of which
> appear to be on-line (although the MF11-U ones might be in the 11/05S print
> set, which ISTR is online).
On looking at the 11/05S print set online, I think it has most of the MM11-Y
prints, but some pages are apparently missing (it claims), so I think not
everything is there.
> I don't think the ME11-L prints are online either, but those I have in
> my 11/05 print set - I'll have to see if that print set is online
> somewhere, no point re-scanning them, if so.
So it turns out that these don't seem to be online (in any form), but I have
a set of hardcopy in my set "PDP-11/05 Engineering Drawings" (which is
different from the 05S set which _is_ online), so I will scan them in and
make them available at some point (especially since these seem to be the most
common PDP-11 core memory boards).
If anyone is desperately searching for them, please let me know, and I will
accelerate that process.
The situation with the ME11-L/MF11-L/MM11-L (which are all the same boards)
is slightly complicated. The board set is called an MM11-L (or -LP,
depending); G110+G231+H214 for non-parity, G109+G231+H215+M7529 for parity.
The MF11-L seems to be a backplane, plus an MM11-L board set; the ME11-L
seems to be an MF11-L in a box.
Some CPU backplanes (e.g. the older 11/05's) can also take an MM11-L board
set. (The _newer_ 11/05's have backplanes which take an MM11-Y - whether an
MM11-L would work in them, I have no idea.)
Noel