I posted this note on Vintage Computer Forums, and thought I'd see if
anyone could help here too.
T actually an acceptable looking TRS-80 Model 1 monitor I snagged for $3
but I figure the principles are the same regardless.
It's dead. No raster and no glow in the tube neck. The board does heat uo
though and there is that smell of old electronics being startled awake
after many years. I've done no tests yet, but I have Sam's Facts for the
model 1, and they provide a troubleshooting guide for the monitor and say
what voltages should be on cetain components. I suspect something to do
with the AC power supply of maybe horizontal sweep. Some faulty power
What I would appreciate from anyone who knows, is a link to a page or doc
which explains how composite B/W monitors work. The Sam's document is great
>from the perspective of troubleshooting detail but it does assume you know,
conceptually, just what's going on. I don't and I'd like to get some
understanding before I start poking around.
Incidently the SAM's fact PDF covers the 110V version while I have a 240V
one. There are some differences, one of which is there appears to be no
fuses in the AC circuits!
My father worked in a mine in the '70s that was using a Honeywell 316 for process control. I was thinking it might be neat to see if I could track one down. What are they worth the days? How common are they?
Sent from my iPad
Does anyone have a copy of the DEC VT125 Maintenance print sheet set?
The mp sheets are DEC part number #MP-01053-00
These should hopefully be slightly easier to find than the VK100 MP sheets.
These are needed for repairing a VK100 and for a project
reverse-engineering how the hardware worked, since it turns out the
VT125 uses an almost but not exactly identical state machine "engine"
for drawing vectors to the VK100. This VT125 information should be
extrapolatable to the VK100 hardware which preceded it.
The Tech manual for the VT125 is on bitsavers as part of the VT100 Tech
manual revision 3 (
starting on page 6-70, pdf page 316)
I'd be more than willing to scan (at high quality) or photocopy the MP
sheets if anyone has a copy they could lend me. A good quality 11x17 1:1
photocopy of the originals is better than nothing, as long as the tiny
labels on the schematics are still readable. (If all you have is a poor
photocopy, though, let me know! A poor copy is better than no copy at all!)
I am fine paying for shipping, handling, finding/digging out of a pile, etc.
P.S. Does anyone have a VT125 and the means to dump the three code roms
on it? I'd love to get my hands on a copy of those as well.
P.P.S. Does anyone have a VT125 and a desoldering station/know-how to
remove and dump the ?five? proms on it? They're not immediately
necessary but it would be convenient to have copies of their data for
the future and to help with potential repairs.
P.P.P.S. If anyone has a not-installed VT100->VT125 upgrade kit which
they are willing to sell, let me know off-list.
jgevaryahu at gmail.com
jgevaryahu at hotmail.com
The 3rd annual Vintage Computer Festival Southwest
http://vintage.org/2012/southwest/ is this August 4th-5th. We will feature a
tour of the Ross Perot collection http://mit-a.com/perotcollection.shtml of
vintage computing, including several sections of the original ENIAC
We will also be adding a special tour of the Cowboy Stadium IT
infrastructure. http://mit-a.com/CowboyStadiumTour.shtml The regular tour
lasts an hour and a half - this one will run slightly longer. The group
tours cost $20 and everyone says it is definitely worth it. We will need to
have at least 15 or so people for this tour, and will need to sign up (and
pay) in advance.?
The VCF SW 3.0 will be at UT Arlington. http://www.uta.edu/uta/ More
exhibitors, vendors, and speakers are registering frequently, so check the
We are still looking for exhibitors, vendors, and volunteers (who get to
A. G. (Gil) Carrick
Museum of Information Technology at Arlington
1012 Portofino Drive
Arlington, TX 76012
817-264-MITA (6482) - gil.carrick (Skype)
As long as you have the certificate of authenticity for copies of
MS-DOS, you can continue to ship product using that operating system.
Medical device manufacturers are doing this because if they change the
operating system, they have to requalify their devices which is a very
expensive process. So they continue to buy NOS copies of MS-DOS, as
long as they have the certificate of authenticity, and use those to
ship their products.
They will continue to do this as long as the cost of obtaining NOS
MS-DOS product is less than the recertification process. Given the
number of NOS copies still in the marketplace, they won't need to
upgrade the OS for some time. There is a local guy who mostly deals
in C=64 equipment that has been making quite a nice side business of
finding NOS copies of MS-DOS for some time now.
You would think so, wouldn't you, but as I said before Microsoft is being very creative. The software that you're talking about is unused, possibly retail or possibly OEM, but in any case the license has not been attached so it can be used on any device (for OEM, provided that the equipment is new). You would think that an OEM license, since it is attached permanently to the hardware, would transfer with the hardware, right? You would think that presenting the certificate of authenticity or other evidence that the hardware was licensed would be enough to show a license, right? Not so fast.
A couple of years ago MS, upon a closer reading of the license agreement, noted the part that says that all copies must be transferred when the license transfers. Most people understood (and probably understand) this to mean that you can't keep any copies because there's only one license, but MS reinterpreted it to mean that if all copies are not transferred then it is not a valid license transfer and the license is invalidated, requiring a new license transfer. They set up a new "Refurbisher Program," whereby people selling used computers can give Microsoft more money to make sure nothing bad happens to their nice business. In an interesting twist, the now "meaningless" original "Certificate of Authenticity" must still be present, otherwise you need to cough up the full retail price should you want Windows - thus, per MS, the computer product the license is tied to is the mainboard (which cannot be replaced unless in cases of failure, when MS may choose to make an exemption if they really feel like it), the COA, and any manufacturer provided backup media, including the "recovery partition" of a disk which, if it is damaged, now appears to nuke your license for Windows. At this point they only seem to be targeting used computer stores selling machines with Windows, but until someone takes them to court and wins it could be anyone they want to squeeze. As noted, one copy of MS-DOS is probably not going to be a big deal, but MS appears to not be taking the "live and let live -after all we've already been paid" attitude and it might get worse.
I found all of this out because of the good part of the program - MS will give really cheap upgrade licenses to qualifying nonprofits using used computers through the same program. Want to check it out? Search MS for "refurbisher program"
Does anyone know (of) anyone running/restoring an IBM 7090, early 60s vintage?
I am about to clear out a friend's collection of vintage computer bits and I may find relevant modules and documentation, h/w and s/w.
|| | | | | | | | |
Peter Van Peborgh
62 St Mary's Rise
Somerset BA3 3PD
01761 439 234
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On Sun, 29 Jul 2012 18:48:32 +0100 (BST), ard at p850ug1.demon.co.uk (Tony
> Incidnetaslly, I never met a school maths or physics teacher who realsied
I must say I cannot understand how you succeeded in getting such
universally and consistently incompetent teachers. During my year in the
UK in the 5th form, *all* of my teachers were intelligent, clueful,
helpful and sensible. Admittedly, it was a private school (not one of
the expensive and fashionable ones) and may have been able to recruit
better teachers. I don't know if the state schools are generally bad or not.
While I'm still struggling with the powers supply in the /84, I
decided to also take a good look at the /05. Amazingly, the power
supplies on this one (1972) are 13 years older than those on the /84
(1985), yet their outputs look absolutely perfect. Plugged in the
cards, and it seems to work, apart from one annoying little thing: one
of the front panel switches is bad. I noticed it when I was
depositing, then reading back some data, then took a multimeter to
determine that it's the switch itself that's broken. Cosmetically it
looks ok, but it doesn't work. It's just one of the address/data
switches, all other switches work fine. Are there any replacements for
these switches to be found?
On Sun, 29 Jul 2012 16:58:16 -0700 (PDT), Fred Cisin
<cisin at xenosoft.com> wrote:
> Except that it's MODE.COM (.EXE? (gotta check a copy sometime, and see
> what the first two bytes are!)) contained [EGA,CGA] options that are
> inapplicable for video boards other than the Compaq ones (that had an
> internal and an external video).
Do you mean "its MODE.COM contained options blabla"?