Given all the troubles I have had with the H7140 in my PDP 11/24 I am
considering whether to replace it with modern equivalents, installed inside
the H7140 enclosure. I am a bit puzzled by the specs listed in the PDP 11/24
Maintenance Card, it suggests the PSU outputs +12V and -12V from the memory
inverter/memory regulator, but the specs for the cards don't mention 12V so
I don't know if I need 12V from the PSU. My memory board is an M8722-BC
(MS11-MB). I can't find a manual or printset for this memory, so I am not
sure what voltages it will need, although I suspect it only needs +5V, +15V
and -15V. Is that right?
I know I will also have to replace the fans, because the ones in the machine
are AC and need 35V.
I am looking for a device that sits transparently in an RS-232 serial line and upon seeing a particular code go over the serial line ((or sequence of codes) will actual a relay (or a transistor). Something with two DB25s or DE9s and is configurable to what code will trigger the output? Some kind of box?
Does anyone know of such a thing? I guess it could be cobbled up with a microcontroller, but hoping to just get something "off the shelf."
73 Eugene W2HX
Subscribe to my Youtube Channel: https://www.youtube.com/@w2hx
I am downsizing. These have been in storage for quite some time.
I am about 25 miles N of Boston, MA and S of Nashua NH. These are both
extremely heavy so no interest in shipping.
Unfortunately I do not have any software for either system.
The I is fairly clean and the kb is effectively new-old-stock with the box.
Possibly unused. Powers on, green mono, single drive.
The III powers on but I can't get a cursor on video (there is a flash at
power cycle). It has seen more use than the I (yellowing, case screws
Photos here: https://photos.app.goo.gl/6vbMnVZsZEkrpFGc8
e-mail if interested rich.bramante+cctech(a)gmail.com.
I'm seeking to buy a Sun Microsystems monitor with a 13W3 interface.
Ideally somewhere around central Europe for pickup in person. But I'm happy to consider shipping options as well.
Background: I'm looking to complete a Sun Ultra 1 build that I've been collecting parts for 🙂
Those who have an interest in vintage HP computing will most likely know of
the HP Computer Museum (www.hpmuseum.net). The HP Computer Museum is the
result of over 30 years of work by Jon Johnston who collected HP equipment
and documentation and systematically catalogued, photographed and commented
on almost all of the over 7,000 items in the collection.
After Jon's death in 2016, I kept the museum website going and worked on
restoring many of the more notable items in the collection to working order,
but the museum has largely been static for the last six years.
Jon's wish was that the collection would eventually find its way either to
HP or to one of the major computer museums, and I'm pleased to advise that
the Hewlett Packard Company Archives (HPCA) has agreed to take over the
entire collection and website.
With only a few exceptions, the museum's entire collection of HP hardware,
software and manuals has now been shipped from Melbourne, Australia, to
HPCA's archival company - Heritage Werks Inc, in Atlanta, Georgia, USA. The
equipment will be catalogued and preserved as a record of HP's early years
in computing, with the ability for HP offices to borrow equipment for
The HP Computer Museum website (www.hpmuseum.net <http://www.hpmuseum.net>
), which has long been a popular reference resource for enthusiasts and
industry on HP's computing history, will continue and be maintained by the
HPCA, through Heritage Werks, with the intent of ensuring ongoing access to
the wealth of information collected by Jon and many other HP enthusiasts
over the last 30 years.
Over the coming weeks and months, the website will be relocated to new
hosting platforms and the curatorship will transfer to Heritage Werks.
This will bring to a close my role in maintaining Jon's legacy in HP
computing. It's been a privilege to be responsible for the collection and
the website and to see the value they bring to the vintage computing
Cracked open my General Magic DataRover 840 to find out what specific MIPS
R3000 variant is in it. However, the only chips that are large enough to be
CPUs are *two* with Bowser logos marked (C)GMI JAPAN GLACIER-01 F840276. The
other chips of notable size are easily identified as RAM, a sound/modem codec
and the inverter for the LCD backlight.
I've seen systems with two CPUs that handle two halves of an LCD (the Tandy
PC-1 and Laser 50 come to mind), but none with a CPU this large. Any General
Magic alums on the list who can explain more about these?
------------------------------------ personal: http://www.cameronkaiser.com/ --
Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser(a)floodgap.com
-- "Endian Little Hate We" -- credits from Connectix Virtual PC 6 for Mac -----
Is anyone familiar with PC-51 and/or CoreNET?
These are IBM 5110/5120 related tools developed by an individual in the
My understanding is PC-51 was an emulator that ran BASIC programs from the
IBM 5110. One keyword new in the IBM 5110 was the "FORMS" keyboard, and
you could define input fields (including type-formatting constraints, like
sequence of letters and numbers) -- and once defined, you could
relatively-easily store all the contents of the fields to a file (on tape
or disk). I'm not entirely sure what format PC-51 supported (e.g. could
read in ASCII text files containing the BASIC programs?). But I always
imagined those customer data entry forms in old Radio Shack or Sears stores
-- large department stores -- being developed in something like this.
And CoreNET, I think was some kind of "null modem cable" that let the IBM
5110 communicate with an IBM PC 5150. The IBM 5110 has 3x DB25 connectors
at the backside (and 1x DB15 cable like what became the "standard" joystick
port on some systems in mid-late 1980s). The external tape and disk system
would use these connectors -- with software driven from the ROS. I've
always imagined it would be possible to "bit bang" across these external IO
pins with some PALM-assembly -- the machine should be fast enough to encode
7-bit ASCII at 300 baud across those pins, maybe 1200. I'm not sure if
CoreNET used or required any async card or the parallel communication card
(that did IEEE-488), i.e. not sure if it was more than just a cable.
But what's more interesting - apparently Sony is now the owner of both
these assets, PC51 and CoreNET. Maybe Hal Prewitt sold it to them? Why
would Sony be interested in it? Anyone happen to know anyone who works at
Sony, or ideas on where to start on even "asking them" about it? Might be
a lost cause these days.
Anyone happen to have a copy of the old manuals of either of these?
I recently bought an Alacron FT200-AT dual i860 card. Basically the
earlier ISA version of this:
It included two manuals but no software. Alacron seems still in business
but they didn't reply to email. I've called twice and noone answers their
phone, it just goes to an anonymous voicemail.
Does anyone have any software? I couldn't find anything via Google or on
I have three DEC RA8x drives that have failed (all of them fault with
"spin error") because of bad photo-interrupter tachometer sensors. After
talking to a few friends, it sounds like this is a pretty common fault.
Photo sensors like this are fairly common, even today, but the specific
parts DEC used are weird and unobtainable.
I designed a little PC board that uses an ITR9606 photo interrupter, a
2N3904 and a resistor as a replacement. Works great - gives a beautiful 5V
P-P clean waveform and with the PCB it's a mechanical drop in replacement.
Just screws right onto the original mounting holes and plugs into the
I put the PCB design up on OSH Park
If anybody needs one you're welcome to order some PCBs and build your own.
The ITR9606 is as common as dirt, and you can buy bags of ten on Amazon for
a few bucks.
I've also put a few pictures on the Facebook DEC Computer Users group. I'd
post the pictures here, but I don't think cctalk accepts attachments. It's
not really worth making a web page for it.