Oh yes, that's looking good :-)
Thank you very much Mattis!
BTW: Some years before I helped to repair and administering the east
german copy of an 11/780.. the Robotron RVS K1840.
The console Processor of this beast was an Robotron K1620, the slowest
PDP-11 ever made but it was enough to load the microcode :-)
The 1620 used two 5,25" Floppies instead of the 8" one in the 11/780.
Best regards,
Holm
Mattis Lind wrote:
> That is a BA11-M box with a H780 supply. The schematics can be found in the
> KC780 document since the front end processor of the 11/780 is a PDP-11/03
> with a RX01 drive.
> In the end of this document there is a schematic:
>
> http://bitsavers.org/pdf/dec/vax/780/MP00534_KC780_Nov77.pdf
>
> Good luck!
>
> /Mattis
>
> Den mån 13 mars 2023 kl 10:57 skrev Holm Tiffe via cctalk <
> cctalk(a)classiccmp.org>:
>
> >
> > Hi all,
> >
> > I have to repair an PSU of a 11/23 n a BA11 Box with an H9720 Backplane
> > (with an KDJ-11A) that has run an CNC milling machine until 2 weeks
> > before now. :-) This is a Fidia machine..never heard about it before.
> >
> > The problem is that a big 19000µF 40V capacitor in the PSU has failed
> > and that I think because of that the 2nd of the two Nidec fans has
> > finally failed.
> > I'm in the process of cleaning the goo from the PSU-PCB, found a burnt
> > 5A fuse and now I'm checking the Semiconductors...
> >
> > The problem is here that the Transistors (and diodes) have uncommon
> > types printed on, an TO220 is named SJE2677, another one is labeled
> > 12652-00 RCA..and so on.
> > I've found a label with "0H780-B" on the PSU.. H780 PSU?
> > Where can I get some schematics from that beast? It is a secondary
> > switcher ist seems.
> >
> > Regards,
> > Holm
> > --
> > Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe,
> > Goethestrasse 15, 09569 Oederan, USt-Id: DE253710583
> > info(a)tsht.de Fax +49 37292 709779 Tel +49 37292 709778 Mobil: 0172 8790
> > 741
> >
> >
--
Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe,
Goethestrasse 15, 09569 Oederan, USt-Id: DE253710583
info(a)tsht.de Fax +49 37292 709779 Tel +49 37292 709778 Mobil: 0172 8790 741
----- Ende weitergeleitete Nachricht -----
--
Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe,
Goethestrasse 15, 09569 Oederan, USt-Id: DE253710583
info(a)tsht.de Fax +49 37292 709779 Tel +49 37292 709778 Mobil: 0172 8790 741
I’m working on a project, and I need to know the age of various tape formats. For example when were 6250bpi 700’ 9-Track tapes or DC600A cartridges introduced? Is there any good resource online that documents this? Wikipedia is of some help, but the older you go, the spottier it is.
Zane
Anyone here have a physical copy of 80 Microcomputing (TRS-80 themed) issue
from August 1980? There is a better quality scan of a page I'm trying to
get.
Thanks,
Steve
We're going to stick to the original title of "Domesticating the Computer"
- since that's more in tune with the intended theme.
TAKE #11: (reference, revision listed below)
https://www.youtube.com/watch?v=aLHcUbVO_G0
And here's the narration situation. My daughter said she'd try it, and she
did :) But here's the problem, she has those painful metal braces. Point
in fact, she got them tightened yesterday and in general speaking for very
long isn't her favorite thing right now. So she's requested to just stick
to being in the Art department (recall, she did the background art and
overall arrangement and selection of the systems).
But, I still wanted to share this Take#12 to show she is real and is
involved in the project :) And also that there were a few visual updates
planned.
TAKE #12: (daughter narration)
https://www.youtube.com/watch?v=2flzdzM-ZKM
Here is a summary of some of the visual updates...
01:11 added the ComputerWorld article referencing Pillsbury Farms and
Datapoint, in case there were any doubters about that. [ the article is
from '73 and by that time they had been using the system for a couple years
- I think the original sales contract is in a museum down in San Antonio
still ]
(she botched the Odyssey audio - and this is a casual draft, so it's just
blanked out)
02:16 added a visual reference to Apollo program (since yes there are some
people who didn't catch what that means)
05:03 updates to the "factory" photos (found shot of Tandy's wave
soldering machine) [ I still am aware and agree the use of the word
"motherboard" here isn't quite right -- but, acceptable anachronism? ]
05:21 (just wanted to point out - some complained I didn't mention the
Sphere, which recently a runnable board was revived and demonstrated; can't
fit em all, and the Sphere is mentioned at the bottom here as one of the
"early competitors")
07:32 looking for more "zip-loc bag" examples (Scott Adams has spoken and
confirms he used "baby bottle liners" - it's a small technicality that I
may just address visually on screen); I'm hoping Ken and Roberta might
have photos of some of their old HiRez adventure in bags, but I suspect
that all burned in their house years ago ('91 or so?)
(I wanted a small segment to explain why Zork couldn't be made available
on cassette tape-- I content that Zork itself motivated the purchase of
many early disk drives :) but that'll be for another day )
07:49 minor updates for VisiCalc presentation (it's so neat that in '79,
it had effectively Freeze Panes, split window, and could do Plotting!) Dan
confirms that yes, "software patent" (lack of it) was an issue at the time
09:46 adjusted to give "credit" of 86-DOS to Paul Allen and Tim Patterson.
13:50 the census report of 8% of "households of computer" is an important
part of the theme
(...some bloopers at the end...)
I now have two (separate) folks who can maybe help with the narration. If
that comes together, then I'll add a note to a review of that in the
description or comments of TAKE #11 and TAKE #12.
-Steve
(voidstar)
Hey all, was Delphi accessible as a bulletin board before 1990?
I'm only finding logos and info about Delphi post-1990.
But for early 1980s, what as Delphi? Was it a telnet-sort-of-thing only
accessed only from universities?
I've searched through early BYTE and PC Mag and just not finding any
advertisements about it.
-Steve
https://www.wired.com/story/why-the-floppy-disk-just-wont-die/
Take what you want from the article, but I thought the end paragraph,
noting that Tom Persky of floppydisk.com is 73 and is only planning to
handle things for 5 more years. After that, he thinks the company will
not transfer to anyone.
Interesting thoughts there.
Jim
--
Jim Brain
brain(a)jbrain.com
www.jbrain.com
I always thought of the distinctions this way (from my basis of exposure from late 1970s through the 1980s) and from a higher educational setting primarily:
Mainframe = repairs required multiple technicians, some possibly there full-time; regular operator(s) present, and a locked door located between you and the machine; entire specialized room with raised flooring, extra-high amperage specialized power sources and wiring, and significant air conditioning
Minicomputer = Vendor still provides a technician (just one) for repairs, who drives in out in a station wagon; only a part-time operator only; an user can be located in the same room; 240-volt wiring, but not particularly outlandish
Microcomputer = Computer can sit on a desk or in a "normal" room; broken computer taken by user to someplace to be repaired or self-repaired; typically one user, and only 120-volt household or office power needed.
Supercomputer = a really fast and specialized version (primarily focusing on high-speed mathematical computations) of a mainframe.
Kevin Anderson
Hi,
I acquired an IBM PS/2 Model 80 (8580-071) today and am looking for
advice on what I should do to check it out before, during, and after
applying power for the first time.
I'll try to get some pictures if anyone is interested.
The label near the power switch says that it's an 8580-071. I have no
idea how that compares to the hardware that's in it.
There are two full size (5¼) hard drives, the controller card. I don't
know what type of drives they are yet, they look to be MFM / RLL like in
that they have the common cable and a per drive cable.
There is a video card that has a daughter-card in the same slot like a
thick sandwich.
There is another card that I don't recognize. The card doesn't have any
external connectors and it looks like it takes multiple (approximately
4"x4") daughter-cards. I am wondering if this is a memory expansion of
some sort.
There are two of what I believe are the memory boards between the back
hard drive and the power supply.
The battery is still in the system, but I didn't see any corrosion and
it's away from the motherboard.
There is also the degrading black foam used for air ducting. Blech.
Q: What things should I do as part of checking out this system. I'd
like to eventually power it up and see what is on the drives (if they
will spin).
I need to physically clean it with a damp rag and get some pictures of
the system.
Please share any pro-tips / gotchas / etc. that you think I could
benefit from knowing.
Thank you and have a good day.
--
Grant. . . .
unix || die
Greetings,
We're making final touches on a short history-video we've been making about
home computers (my daughter, in middle school, has been helping).
If anyone has time/interest to do a review, the draft listing is here:
https://www.youtube.com/watch?v=Z9mgSVJZoFc
Unless anyone spots a gross technical error, we're hoping to render the
final sometime this weekend or sometime this month.
Thanks,
Steve
I wouldn’t normally post anything on eBay, but this looks like something someone should grab. I’ve no clue who the seller is, it’s in Massachusetts.
https://www.ebay.com/itm/295558572706
DEC Digital Equipment Corp VaxStation II GPX system with boards & T K70 untested
ebay.com
It is currently at $300. It could also be converted to a PDP-11 with the right boards. My PDP-11/73 started life as a MicroVAX II, and the BA123 is a great chassis. Of course it’s big and heavy.
Zane
