Okay, I admit it: There are many, many things I don't know. :) And one
of those things came up in a conversation today, and sheer curiosity leads
me to ask:
What, exactly, is a resonant transformer?
The subject came up here about a month or so back - I think it was in
reference to a DEC PDP-8/E power supply, but that could be a mistake -
and a look through Google seemed to only bring me sites about Tesla
coils, which was interesting but didn't really shed light on the subject.
So I'm still curious. :) What does a resonant transformer do that a
conventional one does not? Does it have usefulness outside of Tesla
coils? What would it be doing in an 8/E (or whatever machine it was that
was being discussed at the time)?
Any enlightenment appreciated. :)
-O.-
Allright, so I'm going to the movie theatres to watch Fahrenheit 9/11
(this was probably about two months ago). The movie theatre I pick also
happens to have a conference centre at the lower floors. I'm bored, the
movie doesn't start for 40 minutes, so I go down and behold the exhibit
I hadn't looked at since sixth grade or something. The conference
center, as the exhibit, is owned by Storebrand, a major insurance
company here in Norway. (Storebrand literally means "Big fire", hee hee)
And the exhibit is full of cool old office hardware (old IBM
dictaphones, mechanical cardpunches/sorters, etc). And amongst one of
the cards, I see a COBOL card - PICTURE XX99. Ah ha! The smell of
opportunity! And old punch card paper! (*sniff* Ahhh...)
I call around, and finally end up talking to a man named Dag Wold, who
is the archivist and historian at Storebrand, and he explained that he
was a retired insurance worker that kept tabs on the archive's
inventory.
So, finally, I get to come over and look. And what a sight! Apart from a
metric buttload of cool old mechanical stuff and dictaphones and stuff,
a cool IBM 3270 terminal (I think I'm gonna start a thread on that
too :), a VT102 (what was the 2 for, again?), and a nice TI mini I tried
but failed to boot (The floppy I tried probably wasn't the boot floppy),
and some other cool stuff I really should take pictures of, the crown
jewel of the collection was definately (IMO :) a NORD-10/S minicomputer
with a 9-track Pertec rebrand tape drive. /S means "With various
enhancements, like cache" in Norwegian. Terse language, you see. :P
It's in excellent cosmetic condition. I powered it up, and everything
seemed to be working, but seeing how I don't know the first thing about
pretty much anything from Norsk Data, "working" means "didn't burst into
flames" :)
Enter Johnny Oddene, the webmaster of sintran.com, ex-Norsk
Data-employee, hobbyist, and owner of what was left of ND after they
went bankrupt in 1993. (Pretty much just a warezhouse and a trademark)
I mailed him, told him a bit about the project, and asked him if there
was any documentation or anything availible. He wanted to see the thing,
and we decide to meet up at the Storebrand warehouse.
He powered it up and started toggling and talking with me about the
architecture. And what an architecture!! The most interesting feature is
the concept of levels, which was new to me.
The CPU had 16 levels, 0-15. A 'level' was pretty much a sort of what
IBM would call PSW and Intel called ..was it TSS? Anyway, it describes a
running task with all its registers. The interesting thing, is that the
registers that you'd normally get from RAM with a Load PSW isntruction
or an <Insert Intel equivalent> are actually registers inside the CPU!
You just do a level switch, one instruction, and it switches levels and
immediately continues the other level! Of course, with what ISTR being 6
GPRs and some things like PC and stuff, this would end up with a lot of
registers. But boy, was it fast!
In fact, some customers buying the ND-100, the sequel to the Nord-10,
noticed a significant decrease in performance due to this.
It also would BOOT OVER NETWORKS! IN 1972! In what was called OPCOM
(IIRC), which was a small bootloader in PROM, you could boot from
various devices.
It used to have a disk, but now it doesn't :\
I am impressed at how much he remembered about the machine. Reading his
homepage, I find that this was the first computer he used (And the first
is always special... I envy him starting on such an ingenious arch
instead of a sodding 286 like me)
He didn't, however, remember any instructions, so no toggling yet. You
could also tell the thing to boot from floppy using a terminal over
current loop. However, being the owner of the friggin' company, he of
course has a complete set of docs! And a terminal! Yay! He's promised to
call me when he's heading up to his warehouse so I get a peek, too. I
will of course take pictures if I can get to borrow my (What do you call
people living in the room next to you at an orphanage? Neighbour?)'s
CyberShot.
I will of course start a webpage on this. For people wondering, the
PDP-7 is still where it's always been, and waiting for a wire-wrapper.
Thanks in advance for all the help you all probably will give me during
this project ;)
With excited rgds,
--
Tore S Bekkedal <toresbe(a)ifi.uio.no>
Hi,
As yall have noticed, my (pdp11.nl) mail server died on me while
I was away. Apparently, one of the RZ26L drives in Unibus died.
While testing some of those drives, several others died, so I did
replace all of them with new(er) RZ28's which have proben to be
rock solid.
Dunno how much mail was eventually bounced back, I believe the
problems started wednesday night, soo...
Cheers,
Fred
--
Fred N. van Kempen, DEC (Digital Equipment Corporation) Collector/Archivist
Visit the VAXlab Project at http://VAXlab.pdp11.nl/
Visit the Archives at http://www.pdp11.nl/
Email: waltje(a)pdp11.nl BUSSUM, THE NETHERLANDS / Mountain View, CA, USA
what you want to google for is "ferroresonant power supplies"
http://www.mcitransformer.com/i_notes.html
for example
A ferroresonant power supply is very similar to an unregulated power supply except for the characteristics of the ferroresonant transformer.
The ferroresonant transformer will supply a constant output voltage over a wide variation of the transformer input voltage. The problems with using a ferroresonant power supply include that it is very sensitive to slight changes in line frequency and would not be switchable from 50 Hz to 60 Hz, and that the transformers dissipate more heat than conventional transformers. These power supplies are heavier and will have more audible noise from the transformer resonance than regulated linear power supplies.
Hello all,
My company recently decommissioned a small DEC system. They were
going to scrap it out, but the person who became the "owner" of the
system was loathe to do that, as it was a working system. I spotted
the pile of stuff, and asked about its status. Long story short, I am
now the owner of the system. However, I know *ZERO* about DEC stuff,
so I thought I would make it available to the list. I don't know if
the pile represented a single system, or half a system, or what, but
it is better than dumpstering it, right? :-)
This is only part of the list -- the "small stuff" if you will. The
"big stuff" is still waiting for me to go and get it. Once I get it
and look it over, I will list it here as well (as a teaser, think
B400X, R400X, TS05, RAID array, and MicroVAX).
First, the brief rules:
- Everything is free if you come get it (Westminster MA, USA, ZIP code
01473). If I ship it, I ask shipping +20% (for my time). "Shipping"
includes postage and packaging materials. I buy all of my boxes,
etc., at Staples... Please don't ask me to go 50 miles out of my way
to get a cheaper box :-)
- Please email me *off-list* to indicate yout interest. I will take
emails up until Monday 11/15 at midnight, to give weekenders and
international folks time to see this. I will decide who gets what in
the event of multiple interested parties. I will email the lucky ones
sometime on Tuesday.
- I will try to answer all questions to the best of my abilities, but
remember, my knowledge of DEC systems is less than zero....
OK, on to the stuff:
- Terminal, VT-420 C2, manufactured 7-Aug-1990. Amber screen, passes
diagnostics on power-up. Screen is kind of dim, and also "wavy"
(letters move back and forth at high frequency). Also will need a
good cleaning. Has a keyboard attached, LK-401-AA, rev. A02.
Keyboard is also quite dirty, but appears to be functional (F3 brings
up config. menu, and I could navigate w/ keyboard)
- Terminal, VT-320 C2, manufactured 31-Aug-1990. Amber screen, bright
stable picture, some burn-in, but not too bad. Startup diagnostics
pass. Will need a good cleaning. Has attached keyboard, LK-401-EA,
rev A04. Keyboard dirty, but functional. Has a WordPerfect template
stuck on above the top row of keys. Again, F3 brought me to config,
and I could navigate w/ keyboard.
- Terminal, VT-520 C4, manufactured 1994. Amber screen, clean, but
definite screen burn. Status line is badly burned in, and screen shows
signs of other burn-in. Startup diagnostics pass. Has attached
keyboard, LK-411-AA Rev B01, dirty but functional. I was able to bring up
config and navigate w/ keyboard.
- Terminal, VT-520 C4, manufactured 1994. Untested, because it is
still in its original box. The box is opened, but the styrofoam
packing is there, and the terminal appears still sealed inside the
blue plastic bag it was shipped in. Base is also included, but NO
manuals or keyboard.
- DECServer 200/MC. Has a 15-pin Ethernet connector and 8 DB-25 male
connectors. Also says Model: DSRVB-A. Untested, but working when
pulled.
- ThinWire Ethernet Singloport Repeater-150. DESPR-EE, rev C02.
Looks cleam, missing rubber feet. Untested, but another working pull.
- M9404-PA card. Full-height card. Half is just a plastic spacer,
the other half says "Q22 Cable Connector". Untested.
- M9047 Grant Continuity Card
- Manual: "B400X Expander Installation Guide"
- Manual: EK-BA44A-IN, "Entry Systems, BA400-Series Enclosures,
Storage Devices Installation Procedures" (TWO copies)
- Manual: EK-BA44A-IN-003, "Entry Systems, BA400-Series Enclosures,
Storage Devices Installation Procedures"
- Manual: EK-RF72D-UG, "RF Series Integrated Storage Element User's Guide"
- Manual: EK-RF72D-IM, "RF Series Integrated Storage Element
Installation Manual for BA200-Series Enclosures"
- Plugs, possibly for setting Drive IDs, or Bus IDs? Part Number:
12-28766-19 REV A01. Three plugs with no ID, the rest numbered 0-7.
One full set, one with blanks and 0,6,7 only.
- Plugs, possibly for setting Drive IDs, or Bus IDs? Part Number:
12-28766-28 REV B01. Three plugs with no ID, the rest numbered 0-7.
One full set, one with blanks and 0,5,6,7 only.
- FIVE covers, look like they cover hard drives. 7027049-02, Rev. A01
Thanks!
Rich B.
I've bought a model 33 off eBay. The seller doesn't
really know how to ship one -- he's just got it in a
box with styrofoam peanuts. I'm trying to give him
some instructions on how to do it right. I recall
that
there is a shipping screw that must be locked, but
don't remember the details. Can anyone give me some
instructions I can pass on to him? If anyone has
shipped one of these, I'd like to know what worked and
what didn't. I remember a few stories of machines
damaged in transit showing up on the list.
Thanks,
--Bill
Hello,
Any collectors in or near OC, CA?
I occassionally have things to get rid of, but nothing
particularily valuable.
Examples:
Commodore stuff (VIC,C64).
Portables (Compaq, Osborne).
Books (Apple, Amiga).
and other similar stuff.
Watch for me on the Fox TV show "The O.C."!
Just kidding, it's lame.
Steve.
__________________________________
Do you Yahoo!?
Check out the new Yahoo! Front Page.
www.yahoo.com
Yo Freddie - call me on my landline of cell if your mailserver is still
stuffed up....
obClassiccmp: Found a few nice VaxStationen at Wierd Stuff last time I was
there... an M3100/74 and accompanying Storage Expansion Box with all the
cables intact, including the RGB/kybd/mouse cable. Ain't had time to
power it up yet, but it's on The Canonical List of Things to Eventually
Do.
Cheers
John
