I have an 11/93 with 2MB of memory onboard. I would like to kick it up
to 4MB. I got some memory a while ago that was supposed to be PMI for
it but it turned out to be UNIBUS and thus no help. I have some old
fashioned QBUS memory module floating around. Will these work to add
the missing 2MB or can the 11/93 only use PMI?
Would be nice to wake this old box up again. I have this cool
Decromancer just crying for somewhere to run.
bill
Is anyone familiar with the Type 1138SSM Cartridge Reader by Endeco, Inc
(of Marion, MA) ?
I recently got one, it appears to have an RS-232 interface at the back (and
a power cable). I believe it is from around 1989.
The cartridge slot has a connector that looks like something an NES might
have. That is, it is not a tape, but it is much larger than CompactFlash.
If anyone is familiar with these, I'm trying to find some cartridges and
any kind of manual on how to interface with the thing.
Thanks!
Steve
LSSM is looking for a copy of the RK06/07 Technical Description Manual,
EK-RK067-TD-001.
If anyone can give or loan it to us, we can scan it as well for public
distribution.
Thanks.
Hi
I know this isn't exactly the right group for this. But I have a fairly
uncommon Wang calculator for sale and am not sure where to post about
it. I've tried "Vintage Calculators Buy & Sell" on facebook without much
luck. I see there is some calculator activity on discord, so I'll post
about it there but I'd be happy for suggestion of other venues before I
go the E-bay route.
Below is the blurb I posted on facebook and here is a link to photos of
the thing:
https://drive.google.com/drive/folders/1gNdVSsNDxDL1Ukjh13-2ElJXRiWKQ5rx?us…
FOR SALE: a Wang 362E electronic calculator in good condition, some
scuff marks and light scratches but the inside is clean and looks to be
complete. It comes with the 370K programming keyboard with nixie tube
display in original dust cover, two card readers model 371 (with feet),
four manuals in English and one in Swedish with handwritten notes. Also
included is an IBM port-a-punch in box.
I have decided not to test it in order to avoid causing any damage from
improper handling or due to problems with ageing hardware.
Located in Uppsala, Sweden. I will ship internationally but please allow
some time for me to package it properly and figure out the best shipping
options. I have shipped heavy computers and even CRTs with success, so
I’m not without experience.
Give me an offer :)
Hi all,
I recently got my hands on what I believe is a 9-track tape, dated 1986, which has some old survey data stored on it from a university research project several decades ago. I'm hoping to be able to extract the information from the tape and convert it to a more modern data file accessible to the public, but I don't know very much about these tapes nor do I have 9-track tape equipment.
I'm wondering if anyone who is more familiar with this technology can tell me it's even still possible to extract this data, and if so, is there's anyone here who can try and run the tape, or knows someone with a working 9-track tape drive?
The frame is not in the best shape, but the tape is hopefully fine. Here's a photo:
https://drive.google.com/file/d/1PrdBnIWUO4-317ZSwqvY-TD6dHr2CxC8/view?usp=…
Thanks,
Luke
Recently I got a nice and complete PDP-8/s from the US. The power supply
uses a ferroresonant transformer which in addition to the standard primary
and secondary windings has a separate 2.3H winding connected in series to a
2uF 660VAC capacitor forming a resonant "tank" circuit. The transformer's
secondary side and the resonant circuit are operated in saturation. There
is a magnetic shunt to prevent the primary side going into saturation as
well. It accepts a wide input voltage range, but is very sensitive to the
input frequency of 60Hz. This is quite a nice if not elegant design for the
period in question, but maybe not the most efficient.
As I live in Australia I get 240VAC and 50Hz as opposed to the US 115VAC
and 60Hz.
I can easily convert our 240VAC to 115VAC with a step-down transformer, but
cannot easily supply 115VAC at 60Hz. So I was considering using a step-down
transformer to get the 115VAC, but modify the resonant "tank circuit" for
50Hz.
Unfortunately there is some magic I don't understand. The resonant
frequency of a LC circuit with L=2.3H and C=2uF is about 75Hz not the
expected 60Hz.
Otherwise I could just solve the standard LC resonant circuit formula for C
and plug in 50Hz and 2.3H to get the required C.
Obviously ferroresonant transformers are more complex than this former
software engineer can grasp. Could any experienced EE with relevant
transformer knowledge please chime in and help me understand how to
redimension the tank circuit to use 50Hz instead of the original 60Hz input.
Obviously I could replace the entire power supply with two modern switch
mode supplies to create the two rails, but it would be really nice to keep
the original supply and just reversibly adapt it for 50Hz.
Thanks and best regards
Tom
At 04:22 PM 7/10/2025, you wrote:
>Lee Felsenstein at VCF West Friday, August 1 at 4:30PM.
>He will talk about the 50th Anniversary of The Homebrew Computer Club.
Here's the line-up:
https://vcfed.org/events/vintage-computer-festival-west/vcf-west-speakers/v…
Not just Lee... but also Bob Marsh of Processor Tech, and Harry Garland of Cromenco,
and Dan Sokol of Apple...
And then for the Amiga 40th events, Dale, RJ, Trevor, Perry, Willie, Marco,
Bill, Aaron, Brad, and me, too!
And Sellam is there!
- John
