When contemplating spending some fairly serious coin on that IBM
system earlier this week, a friend asked "which systems/machines out
there would you pay 'real' money for?" Since I'm not a Big Iron
collector, and I'm used to spending no more than $10-20 on any given
piece, that's a fair question for me. Maybe a Symbolics Lisp machine.
Maybe an original Sun machine, or even a 2-series. A Xerox Alto.
Historical stuff like that. Then I remembered when my high school
class took a trip down to the U of I at Champaign-Urbana for
"Engineering Open House" and I was sat in front of this monstrous
wooden terminal with beguiling orange vector graphics. Only many
years later did I learn what it was, and where it fit in the timeline
of computing (thanks in part to Ted Nelson's "Computer Lib/Dream
Machines" books.)
So...who has one? What's become of the remaining infrastructure? I
recently used a Windows Plato client to connect to some descendant of
the system, but I asssume even the back end was running on modern
hardware then, and not old Data General equipment.
-j
--
Retrocomputing and collecting in the Chicago area:
http://chiclassiccomp.org
I'll never know unless I ask - does anyone have a TU56 for sale or
trade?
Ideally in the $10/lb range, or trade for an Altair 8800. I'm in the
Chicago area, will be driving to VCF East and Midwest in the next few
months, happy to drive a couple hundred extra miles to retrieve said
tape drive. Shipping is a bit frightening, but will certainly be
considered.
The drive will be interfaced to my 8/E, most likely with a TD8E
interface, but a good or restorable unit in any configuration will do!
TIA,
Jack
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6:40 PM
Hi All
For reasons that I will not go into here I have most of four
PDP-11/94's. The 94 was the last of the PDP11 line. Thats about as
classic as it gets.
Notice I said 'most'. What's missing is the cpu cards in this case a
KDJ11-EB. The DEC orientated amongst us will know that the CPU is a QBus
J11 chip based board on quad module (M8981). Ah but the 11/94 is a
unibus system you say. Thats right. The board talks to the unibus
through a KT11-B that does the conversion.
Now for my dilemma. Before checking the cost of a KDJ11-EB you are
advised to make sure pacemaker batteries are fully charged and any blood
pressue medication has been taken. Take it from me the prices are so
high they need to join the astronaut corps!
I would like to get at least one of these historic systems running
again. Suggestions please!!
Rod Smallwood
All:
I have a few IBM-labeled YE-Data YE-580 (320k/360k) half-height floppy
drives. I can?t seem to locate a manual for these on-line so I wondered if
they use the standard 150 ohm terminator or something else (the Teac uses
330 ohm for example).
Any info appreciated. Thanks.
Rich
--
Rich Cini
Collector of Classic Computers
Build Master and lead engineer, Altair32 Emulator
http://www.altair32.comhttp://highgate.comm.sfu.ca/~rcini/classiccmp
> they never find stuff on
> bitsavers when you search for text.
Very early on, I disabled all search engines from .pdf files
on bitsavers' in the robots.txt file.
Google is particularly bad about fetching documents over and
over again.
My best-condition 83-key keyboard suddenly developed a bum spacebar,
right in the middle of writing some documentation. Before I unscrew the
two screws on back to open it up and take a look, can anyone tell me if
this is a common condition and if it's relatively easy to fix? I've
*never* had a buckling-spring keyboard develop a bad key (maybe I
haven't had enough frustrating debugging sessions yet ;-) so I'm at a
slight loss as to how to start repairing it. Was there a tech ref for
the keyboard at one point, perhaps?
Slightly OT, here's an 83-key that is *gray* (several pictures):
http://www.clickykeyboards.com/index.cfm/fa/items.main/parentcat/11066/subc…
I've never seen a gray variant -- was it official? If so, what system
was it intended for use with? I've seen "skinny" IBM keyboards that
were intended for use with the PS/2 model 25, but I've never seen a gray
83-key before...
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Help our electronic games project: http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
A child borne of the home computer wars: http://trixter.wordpress.com/
At 12:02 -0500 5/6/07, Pat wrote:
> > Au contraire. "Architecture" these days is whatever you want it to be
> > cooked into an FPGA. .... FPGA designs are
> > *very* popular for custom architectures these days.
>
>Sure, but no one (in their right mind) builds a general purpose CPU out
>of them. Well, unless it's a research or "toy" project, a prototype
>design, or something very unusual and high end[1], but even in that case
>it's still not making a general purpose CPU out of it.
Although I tend to agree with Pat about the "right mind" part of it,
we routinely do this for spacecraft avionics. Both simple processors,
like 8085, and more complex ones like SPARC architecture are
implemented in FPGAs. The speed is generally far below what a "real"
CPU would do, but because we can implement more functions than just
the CPU into a single chip, and because we can often get an FPGA that
has been tested to better radiation exposure levels than the
corresponding (faster, smaller semiconductor feature) "real" CPU, it
still turns out to be the best option in many cases.
I really mourn the lack of availability of rad-hard CPU's anymore.
Harris RTX2010 (a forth-oriented 8/16 bit) and the RAD6000 (a
PowerPC-like unit) were both workhorses in the past. The FPGA's we
use routinely come up with chip-level problems of one form or another
(bad programming algorithms, power-up sequencing issues, etc.) that
cause angst, board reworks, or other serious cost and schedule
problems. That never used to happen with "real" CPUs.
>I challenge you to come up with the name of a single product that someone
>can purchase right now, which uses an FPGA-implemented CPU, which is
>general-purpose, and reasonably widely available.
:-) admittedly, I can't really claim our avionics boxes are "widely
available", though we're always looking for new customers....
--
- Mark, 210-379-4635
-----------------------------------------------------------------------
Large Asteroids headed toward planets
inhabited by beings that don't have
technology adequate to stop them:
Think of it as Evolution in Fast-Forward.
Thanks to another cctalk-er, I've discovered an inexpensive
replacement for the dreaded neoprene belt in Amstrad 3" CF drives.
There's a product called "Plastibands" available at many office
supply stores (or on Amazon.com) that are intended as a replacement
for traditional rubber bands. They're made of polyurethane and have
a considerable amount of "stretch"--and, the best part, don't
disintegrate quickly. I slipped one of the 2" x 1/8" bands on my CF
drive and it works like charm--plenty "grippy".
A box of 100 on Amazon runs less than $5.00. That should keep you
and your best friends in drive belts nearly forever.
There's also a larger 4" x 1/4" size.
The $64,000 question is "Can these be used as a replacement for the
band in DC-600-ish QIC carts? My initial experimentation with the 2"
model in a DC-2000 cart is "not quite"--the QIC application requires
a bit of slip, which these don't appear to have--they're a bit too
"grippy". However, I'm going to tumble a few in some molybdenium
disulfide powder for a few days to see if a "slip" can be imparted to
them. Stay tuned...
However, I suspect that the larger belts might work with old 5.25"
floppy drives that require a drive belt. Remember, as they stretch,
they get narrower.
Cheers,
Chuck
Re: "The spacebar - beyond the switch - has a small "C" supporter that keeps
the bar horizontal and makes any pressure in any point of the bar activate
the switch"
This is called an "equalizer" mechanism, and all keyboards have it on all
large keys (it's usually present on the enter and shift keys as well as the
space bar, and often on a few other keys). These can be a real bitch to get
reconfigured properly, but it's a purely mechanical task, and with some
patience, if this is the problem, it should be fixable.
It's possible, however, that this isn't the problem. Do NOT take the back
of the keyboard apart as a first step, rather, remove the space bar (being
very careful not to break the equalizer mechanism and noting in detail how
it is attached). There is a metal plate inside the "switch" that serves as
the actual contact point, this can become dislodged. Or there might be dirt
in the mechanism. It's very rare that these can't be fixed, and fixed
without any new parts, unless something is really broken. More common it's
just dirt or some mechanical part that has become misaligned.
