Tony Duell wrote:
> The 555 even has regulated heater supplies. The heater
> transformer is fed
> through a saturable reactor. The current in the control
> winding of that
> comes from a pentode valve in the PSU unit, the grid
> voltage of that is
> controlled by a bright-emitter diode running off one of the
> heater lines.
> So the thing actually gets the RMS value of the heater
> supplies correct
> (which is what you want, of course).
That's fascinating. I'd seen "passive" ballast tubes
for heater regulation, but not an "active" solution like
this. I found a good write-up at:
http://www.radiomuseum.org/forum/2as15_how_it_works.html
Especially interesting to me is the mechanical link in the
diode that shorts it out when the filament burns out, pulling
down the regulated voltage. I wonder if they learned the
necessity of that the hard way.
John Finigan
Just ran across this list. I thought I'd share this with all of you.
http://www.youtube.com/watch?v=am60T-p7f1E
This was when I was working at NASA Ames -- NASA Science Internet (NSIPO), Building N-233. I had a Sony Hi8 I just had bought and was testing out. I'm surprised I kept this footage.
Enjoy!
Rob Gutierrez
For those who want it (cost of postage + $20 for the 'bribe') :
I have about 20 boards from 2 HSC-70's cluster controllers
and several floppies which came with them.
All the boards together is about 12Kg in weight.
Ed
--
Certified : VCP 3.x, SCSI 3.x SCSA S10, SCNA S10
On Nov 6, 2009, at 2:41 PM, Dave Woyciesjes wrote:
> >
> >
Date: Fri, 6 Nov 2009 14:48:33 -0500
From: Dave McGuire <mcguire at neurotica.com>
Gezundheit.
-Dave
Thank you...
(BTW, switched to digest for now...)
Yeah, I had to go back and look to make sure I really sent a blank
message like that. Must've been when I was tinkering with the new (to
me) iPhone 3G.. Well, it's just an iPod Touch now, since it's not
getting any cel signal; and I have no justification for paying out the
nose for the data plan....
Now to figure out how to get the iPhone Mail to have different sigs for
different accounts...
--
--- Dave Woyciesjes
--- ICQ# 905818
--- AIM - woyciesjes
--- CompTIA A+ Certified IT Tech - http://certification.comptia.org/
--- HDI Certified Support Center Analyst - http://www.ThinkHDI.com/
"From there to here,
From here to there,
Funny things
are everywhere."
--- Dr. Seuss
Please feel free to repost on other forums, I'm trying to catch as many
people as possible:
As many of you are probably aware, I acquired a license to sell JiffyDOS
earlier this year and am now ramping up sales.
To that end, I am trying to reconstruct the exact product offerings that
CMD offered. This means verifying images, and determining what original
ROM images CMD supplied with each overlay.
Thus, if anyone can use a DOS ROM reading utility (or EPROM reader) and
can send me a copy of the both halves of the JDOS ROM, I'm still
struggling with the following systems.
1571: I have three versions here, but cannot determine which is correct.
The MD5s are: 41c6cc528e9515ffd0ed9b180f8467c0,
6b4d46b28b7414d5a82cea4972894600, and d649fa6b0108c20ce213f5496d5980a5.
What is the version number on the ROM sticker?)
1571D: I have a 1571D JiffyDOS ROM here, but it looks to be a 1571DCR
(the cost reduced version). Notes indicate a non-CR 1571D used a normal
1571 JD ROM overlay, but I'd like to verify that.
MSD SD1/SD2: I am trying to determine the version of MSD code in the
lower half of the U5 JiffyDOS for SD2. The MD5 is
1a2efac3b96decf83fba27bc17c5a8a7. I checked against my SD2-2.3 version
here, but they are different. Also, is the SD1 JiffyDOS the same as SD2
version?
Indus GT: I do not have an original JDOS for this, so I need a dump to
compare.
1541C: Again, I do not own an original JDOS for this machine.
I understand there is a Swedish version of JiffyDOS for the C128 and
C128D (and possibly for the C64) [Update: I have been sent copies of
the Swedish JiffyDOS ROMs, but I'd still be interested in what version
of KERNAL was included as the "original" KERNAL for these units.]
German/Finnish JiffyDOS variants?
Any help folks can provide would be much appreciated. In fact, if you
have an original JDOS, no matter the type and can dump it for me (both
the original and the JD portions), that'd be great. Anything you can
tell me about the setup - sticker legend (version number, etc.), machine
variant (128, 128D, 128DCR, etc.), video standard (PAL/NTSC), and
whether it had a switch on the ROM - is good information to share.
To clarify, I know there are bootleg archives available, but I can't
consider them authoritative. In addition, the archives would not tell
me what CMD placed in the non-JD half of the EPROM on units with
switches. I would prefer to check against genuine copies of the
overlays if at all possible.
Jim
--
Jim Brain, Brain Innovations (X)
brain at jbrain.com
Dabbling in WWW, Embedded Systems, Old CBM computers, and Good Times!
Home: http://www.jbrain.com
Having the day off, I finally uploaded some new pr0n to the Alpha Micro Phun
Machine, including pictures of the AM-1000 and AM-1001 I got recently, and
the AM-1041 S-100-based system that I'm hoping to restore and get operational
in the not-so-distant future (hi Bob!). I also included a download for the
fingerproxy, which I'm using to give arbitrary TCP socket access to older
AlphaTCP installations. Maybe I'll work on Lynx for the Alpha Micro next ;-)
Anyway, http://ampm.floodgap.com/
Running on a real Alpha Micro Eagle 300 since 2007!
--
------------------------------------ personal: http://www.cameronkaiser.com/ --
Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser at floodgap.com
-- "My inner geek can beat up your inner geek." -------------------------------
Jules Richardson wrote:
> I'm not reading here much at present, not until I
> eventually get all my
> collection moved, but I did just get offered a Tek 545A
> which is languishing
> in a garage down in Texas, so figured I'd ask about
> shipping it safely.
Cool! I had a similar one, a 543 IIRC, that was the only
major piece of tech-junk I lost to hurricane Katrina.
I still grin thinking of my complete panic when I looked
at one side panel and saw a big orange glow in the tubes
next to the power transformer. Got the side off and
realized it was a neon filled voltage reference tube,
not a glowing plate.
Anyway, the things are a treasure trove of interesting
tubes. I like the tiny soldered-in (baseless) HV
rectifiers, tube regulated B+ system, and the
electromechanical time delay "tube" that lets the
thing warm up before applying HV. It's interesting to
see tube design in "cost not much of an object" mode.
I used to have Stan Griffiths' book "Oscilloscopes:
Selecting and Restoring a Classic".
I don't remember it being particularly technical, but
it has tons of info on the Tek tube-era product line,
and was fun to thumb through, if you're into that
kind of thing.
John Finigan
I was considering parting out these boards for the chips and caps but realized that was really dumb. My ttl hobby is based on using parts in my junk boxes or parts paid for by other things in the collection. To that end I am offering these 5 boards and one manual. Three of the five boards have had the bus connector removed, some have a few chips removed. Please look here:
http://picasaweb.google.com/jjgessling/ComputerStuff#
Please let me know what you think, I can certainly ship.
Regards, Jim
I am finally testing out the pile of DEC VT420s I recently came into.
Here is the deal:
These are in decent, but sometimes a little grungy condition. I will
test them out, and make sure the video is good, the comm port is good,
and the keyboard is good. I will let them sit powered on for 15
minutes as a simple burnin. I will not clean them. They will be packed
very nicely.
$25.00 plus S&H from 10512. These weigh roughly 20 pounds unpacked.
Please reply off list.
--
Will
