All you Tekkies out there...
I just pulled my old Tektronix 4051 out of the garage (no I don't want to
sell it), plugged it in, turned it on and ... and ... and ...
Well all the lights lit, the memory CRT bloomed, and that was that.
Screen wouldn't clear and the machine wouldn't respond to any keystrokes.
It's frozen...
Well it worked fine when I put it in storage and I was wondering if anyone
had any experience getting these to work after years without juice?
I seem to recall that the machine goes through a self-test on power
up: the "busy" and "i/o" lights light and after a few seconds they go out
and a square cursor appears on the screen. Does anyone remember what the
self-test looks for? I'm thinking it may try to trigger the tape to rewind
and wait for the results. I don't know why any electronic part would fail
after years of storage but would seem likely that a tape drive motor might
seize up and stop the machine from completing its test.
It would be an easy matter to free up a motor and a more difficult matter
to diagnose a parts failure. Any ideas before I take the thing apart?
Thanks in advance...
Nick
Nicholas Gessler
gessler(a)ucla.edu
Box 706, 22148 Monte Vista Drive
Topanga, CA 90290-0706
310.455.1630 (home office)
310.825.4728 (UCLA office)
310.825.7428 (UCLA fax)
Special Projects, UCLA Center for Digital Humanities
Founding Co-Director, UCLA Center for Social Complexity (a.k.a. Center for
Computational Social Science)
Founding Co-Director, UCLA Social Interfaces & Networks / Advanced
Programmable Simulations & Environments (SINAPSE)
Instructor, Geography, Computational Geography Track: Simulations,
Cartography, Artificial Culture
In preparation - "Artificial Culture - Experiments in Synthetic Anthropology."
Web Portal:
http://www.bol.ucla.edu/~gessler
Just for those who aren't aware of the proper uses and display of the US
flag in this moment of everyone just having to display it lately, here's a
well done resource for reference. This is a guideline made from US Public
Law 93-344 and done in a layman's format so it's easy to grasp and use. It
might even be a good idea for local newspapers to print a variation of this
once to inform people that don't know that they may be "doing it wrong"
http://www.state.wi.us/agencies/dva/museum/flaguse.html
Went to the Columbia (Maryland) ARA hamfest this
morning. By far, the most successful, in vintage
computer terms, hamfest I've ever been to.
Arrived at 6am. Dark... Walked around through
the little bit of fog, squinting at the tailgating
stuff already out. Silly me, forgot to bring a
flashlight. Talked to some people and got a line,
maybe two, on an ASR 33. As the sky gradually
brightened, made my first score, a box of S-100
cards and motherboards. The guy wanted $20. I was
so amazed to find anything that interesting that
I forgot to haggle and handed him a twenty. Next
I found a large pile of 50 pin twisted pair rainbow
wire (perfect for 8 inch floppy cables) for $1.
It quickly got lighter and the fog burned off. Now
I could see the following of classiccmp interest
(all of which I passed on):
A pile of 20 or so Commodore 64s with a sign "2 for $5"
A large collection of SGI boxes, Indigos, etc.
A large collection of Sun boxes and monitors.
A number of Atari boxes of various makes.
A table with 10 or so old Mac boxes and a Next slab.
A couple of CoCos.
A lot of tailgaters were still setting up, but it was
8:30 and I had to leave. On my way out, a flash of
"S-100 blue" caught my eye. In an unattended box
labeled "project enclosures, $5 for the box, slip money
in drivers side window" was a really nice, clean NorthStar
5 1/4" disk enclosure with power supply, but no drive. I
didn't need all the other Radio Shack style project boxes
that were also in the box, so I just took the N* box and
put $2 in the window.
I hope some other CC'ers made it to this one, I'll
definitely be back next year.
1) Power on the machine.
2) Wait approximately ten minutes.
3) Press 'reset'.
4) Wait a further thirty seconds.
5) Type <CTRL>-V on the console keyboard. The machine should beep.
6) Type '1' to set the video system to 70 Hz sync or '2' for 60 Hz.
additionally, the default mode for the serial console (which the system
will automatically use if there is no keyboard plugged in at power-on) is:
9600-E-7-1
Good luck. Hopefully this will help somebody get his Aviion going.
ok
r.
On September 19, Chuck McManis wrote:
> So does anyone have a preferred way in which they organize all the many
> hundreds of bits of stuff you need when you are keeping older computers alive?
For storing stuff in boxes...I avoid cardboard nowadays...I've been
replacing them with those plastic "tubs" that one can purchase at
discount stores. They last longer, are waterproof, and more
stackable. They've also considerably cut down on the dust level in
the house.
-Dave
--
Dave McGuire
Laurel, MD
I'm looking for parts to repair a dead? eMate 300. The screen is basically
cracked in half! Fortunately, the rest of the unit is intact. For those who
don't know what one is, this is basically a Newton-based laptop and a very
nice little machine. I'm scoping around for parts but was wondering if
someone had a dead one with an intact LCD they might be willing to part with.
Ironically, it was damaged in a classroom demonstration of how difficult to
break it was. The professor nailed it the first time. :-/
--
----------------------------- personal page: http://www.armory.com/~spectre/ --
Cameron Kaiser, Point Loma Nazarene University * ckaiser(a)stockholm.ptloma.edu
-- In memory of Howard Caine --------------------------------------------------
On September 19, jkunz(a)unixag-kl.fh-kl.de wrote:
> BTW a stupid question: What is a 8700? Is it SBI based like the
> 11/78[05] and 86[05]0, or is it XMI / VAXBI like the 85x0 or 6k VAXen?
> I asume that a 8700 is a 8600 in a biger enclosure?
The 8700 and the 8600 are very different machines. The 8700 uses
VAXBI, and is mounted in a chasiss similar in size to that of the
8600. I don't think there's any XMI in there.
Incidentally, the 8700 can be turned into an 8800 by plugging a
second CPU card set into the machine.
-Dave
--
Dave McGuire
Laurel, MD
On Sep 22, 13:11, Roger Merchberger wrote:
> I did mention that I was primarily a softee-ware guy -- and when
> dealing with chips I have a tendency to think of them *as software* --
> like: if you try to write to a ROM, what happens? Nothing. (duh...)
Well, not unless you use "more interesting" voltages :-)
> I
> looked at the chip specs for the demux, and you have inputs & outputs...
In
> my mind (at first), your suggestion was "ramming 5V down an output port"
> and sometimes I have to stop & think that "those ports are just a bunch
of
> gates jammed together on a chip to serve one purpose" and doing stuff
like
> that is not a "Bad Thing (TM)." :-)
> My board isn't a "complete" board -- it's to be designed to make
> experimenting much easier by having flexible on-board address decoding,
and
> (at least for my purposes) I want "one address per switch", so I'm not
sure
> if the MUX suggestion is what I want. As of right now (but I'm still
> researching CoCo memory maps) I'm looking to have an 8K ROM socket at the
> "normal" location ($C000-DFFF) w/jumper as to whether or not it will
> auto-start (jumpering the Cart signal to the Q line) and I'm looking at
> having the address decoding for my I/O ports at $FF50-3 & $FF60-3, but if
I
> want *just* $FF51 & $FF53 to be decoded & $FF50 & $FF52 to be ignored, I
> want to be able to switch them individually.
> (Originally, my design was just going to have 1 address decoded from each
> "bank", but then I realized that if I wanted to interface "most anything"
> like a PIA, UART or a FDC that it wouldn't work.)
Let's see if I'm interpreting this correctly. I think you want to be able
to decode addresses, but sometimes you want to be able to provide (let's
say) two "enable" outputs, each active for a separate group of addresses
(maybe two different ranges of four addresses each), and sometimes you want
to be able to provide more finely selected enables (maybe responding to
only one address in each range).
I can see why you'd want to that if one day you are using a UART that needs
four addresses and another time you use a a PIO or VIA that needs 8 or 16
addresses.
A couple of ideas that come to mind are using a PROM or PAL to do the
decoding. A PAL or GAL would probably operate faster than a PROM, but it
might be easier to program a PROM (depending on how used you are to
building tables for PROMs, logic rules for PALs, and what programming tolls
you have access to).
For example, suppose you have a PROM with 8 address and 4 data outputs.
You could fill it with data such that certain data outputs were at the
appropriate "active" level if (and only if) 6 of the address lines were in
a certain state, ie were driven with a certain address(es). By tailoring
the data appropriately, you could arrange it so that the outputs took
account of all 6 address bits, or just (say) four). The other two address
bits I'd use as a function selector: if both are low, the output is active
for a range of addresses (only 4 bits significant); if one is high, respond
to the first two addresses in the range; if the other is high, respond to
the upper part of the range; if both high, respond only to the highest
single address in the range. Or something like that, to suit the job in
hand.
Depending on the exact requirement, you might still be able to do this with
a MUX or two. A multiplexer is a very useful general-purpose logic
element, widely used as a circuit building block, not just for the obvious
"if the clock phase is high, select the refresh/video addresses; if low,
select the CPU addresses" sort of operation.
> For anyone here who does their own hardware designing, what software do
you
> use? I've tried "Protel 99 SE" and CircuitMaker 6 (student version) --
and
> a few others, and I must say that I'm not keen on most anything I've
tried
> compared to "good ol' AutoCad".
I use an assortment. Often I use the drawing package from RISC OS on one
of my Acorn machines. From time to time I've used 'pcb' on a Unix system.
> Oh, I've found a really good site to purchase all manners of circuit
board
> "stuff" w/really good prices, too:
> http://www.web-tronics.com/printed-circuit-board-supplies.html
That's encouraging. Completely home-made PCBs seem to be a relativley rare
occurrence in the US, at least compared to here. Over here, almost every
secondary school, college, and university makes PCBs and there are still
magazines publishing designs which enthusiasts photocopy onto film (OHP
acetates, aka viewgraph foils for you colonials) and then apply to
photoresist copperclad board. In the USA, as far as I can see, most people
tend to pass the artwork or plotfiles to professional PCB houses to be made
up. Lots of people do that here too (I'd probably not try to etch my own
board for a really densely packed device using PGAs, for example) but
there's still a strong tradition of using your own ferric chloride (not in
the wife's best stainless steel sink, though).
While there's nothing at all wrong with either method, I'd caution anyone
trying it, that layout software (or dry transfers) tends to be suited to
one or the other but not both. For the professional house, you are more
likely to want nice round pads and not too many different sizes. You can
use thin tracks, and pads with fairly small margins of copper round the
holes. However, for truly homemade, handetched boards, there's usually
more variation in the quality of the image transferred to the board, so
very fine tracks are not such a good idea. Moreover, they won't normally
have plated-through holes, so it's wise to use larger pads which won't come
unstuck too easily -- often oval pads for ICs, which have a relatively
large copper area yet are still narrow enough to leave a gap to get tracks
between the pins. Lots of PCB layput software isn't capable of doing
anything other than simple round (or square or symmetric octagonal) pads
and is therefore much less useful for home-etched PCBs.
No offence intended Roger, but I think your IC pads on the CoCo board are
smaller than I'd personally be happy with for a home-etched and -drilled
board without plated holes. (See
http://www.dunnington.u-net.com/tmp/coco_pcb.jpg for a modified fragment)
BTW, did you notice the tracks going through the pins on pins 13 and 14 of
the leftmost LS244?
--
Pete Peter Turnbull
Network Manager
University of York
