Hey folks;
The Personal Computer Museum (http://www.pcmuseum.ca) is
offering a beautiful 2018 vintage computer calendar as a fundraiser. The
calendars are in hand and the cost is $20 Canadian (no tax).
The
shipping rates (in CAD) are $3.50 within Canada, $5.00 to the U.S. and
$10.50 to the rest of the world.
We accept Paypal via our website at
http://www.pcmuseum.ca/shop.asp
If you don't like Paypal, e-mail me
directly for other options!
The order page includes a sample of what it
looks like.
The computers included this year are:
IBM PC (1981), Kaypro
II (1982), Pencil II (1984), Exidy Sorcerer (1978), Commodore PET 4032
(1980), Apple ][+ (1979), Apple PowerBook 150 (1994),
Commodore 64
(1982), NeXTcube (1980), Superbrain QD (1979), Atari 800 (1979), Unisys
ICON (1986)
If you are interested please reply here or to
info at pcmuseum.ca .... The quantities are limited.
Thanks for your
support!
I was not able to get access to any of my notes to more completely answer
Eric's question.
Short answer: NO. Otrona did not have two different obscure numbers of
tracks for their disk sides. On the limited number of Otronas that I
encountered. What I encountered was very straight-forward WD-like
ordinarty disk formats. IIRC, they were 10 sectors per track, with 512
bytes per sector.
There were 40 cylinder and 80 cylinder.
There was a CP/M, and an MS-DOS.
I don't remember what the distribution of those formats was, although I
specifically remember a 96tpi (800k) MS-DOS.
Ironically, the first one that I saw was a doctor at a hospital.
To flog the point about portability, Otrona did an early ad with a Chaplin
imitator trying to carry a card table with a PC on it down steps in front
of a building (capitol?) IBM claimed to own Chaplin (and did apparently
pay royalties to Chaplin estate), although Chaplin himself was not a big
fan of biug corporation.
I wasn't able to answer more fully, nor even now. I just spent a week in
the hospital. giant kidney stone and massive infection. First few days
were intolerable levels of pain. I am now on 2 weeks of 24/7 IV
antibiotic infusions. Bizarre little pump that I carry around, but, at
least I'm carrying it around at home, instead of the hospital.
THEN, in 2 weeks? they will operate to try to remove the stone. They are
hoping to do it with trans-urethral laser, with lithotripsy as a fall
back.
I had not prepared for being in the hospital, so only had a phone (Samsung
Galaxy S4), and it wasn't until the third day that I was able to wrangel
access to my pants (and pocket contents)
I think that I will recover.
THANK YOU to the folk who wrote to me with good wishes!
--
Grumpy Ol' Fred cisin at xenosoft.com
>From the Otrona Attache Technical Manual, July 1983:
"The diskettes Attache uses have fourty-six tracks on the top side and
fifty tracks on the bottom side, [...]"
Really???
> From: Rob Jarratt
> when I replaced it and powered on there was a big bang
What went 'bang'? (I assume if there was a loud noise, it mus have left
visible damage somewhere.)
Noel
> From: Aaron Jackson
> Picked up a few 555s and sockets and now it works!
Congratulations!
It's odd that a 555 failed, but sometimes there's no rhyme or reason to what
fails. E.g. I was fixing some broken M7859's (KY11-LB Programmer's Console),
and on one of them a 7493 (4-bit counter) had died. That's not one of the
'problem' 74xx chips, like ISTR the 7474 being?
Noel
My last email was unclear...I have a few RK06 Data Cartridges and an
Alignment Cart Available. Contact me privately if you have an RK06 drive
and you're looking for carts. They look like RL02's maybe a hair thinner.
I paid a small amt, and I am looking to be reimbursed for the cost.
I have no RK06 drive. RK06 cartridges are NOT compatible with RK07's
according to the manual. If you're in the Landenberg, PA area stop by,
At some point I will publish a list of other DEC items I have in clean
organized storage.
Bill
> From: Jon Elson
> I'm not sure the original DEC PDP-10 (KA-10) used microcode
No, it didn't; in part because it pre-dated fast, cheap ROMs (the development
of which was a considerable task in the /360 project - the wonderful "IBM's
360 and Early 370 Systems" covers this is some detail). The KA10 is built out
of FLIP CHIPs which carried individual transistors.
Another fun KA10 fact: it used 'hardware subroutines' - i.e. a clock pulse
would get to a certain point, and get conditionally diverted through some
other circuitry, later to come back and continue where it left off. Whee!
Noel
I have numerous BA350 and BA356 enclosures available along with the power
supplies, etc.
I will sell separately, or try to configure to your request. Please contact
me off list.
Shipping from 61820, Champaign, IL area
Thanks, Paul
Hi everyone,
I've been trying to figure out what is wrong with the 12V rail on my
H7861 (BA11-S) power supply. It's showing about 4.2V. The 5V rail is
spot on.
Page 39 of the following schematics is the main part board of the PSU.
http://bitsavers.org/pdf/dec/qbus/MP01233_BA11-S_schem_Mar81.pdf
Going into the collector of Q3 is about 80V coming straight from T2 (I
think I measured it at about 100Hz), but the emitter is putting out the
4.2V, which is the same as the base voltage and output voltage. I tried
replacing this transistor because the hFE was about 80 and a good one
was about 120. Unfortunately it didn't do anything.
None of the capacitors look swollen and I don't see any leakage. There
is a smaller board which I think goes into J4. The 12V side seems to
have a 555 timer and adjusting the pot doesn't change the voltage at
all.
My understanding of switchmode power supplies is very poor. Does anyone
have some pointers on what to check or what might be the possible cause?
Hopefully I can get my PDP up and running again... Only got about 20
minutes use out of it.
Thanks!
Aaron.