From: HOTZE <photze(a)batelco.com.bh>
<Hello... some time ago, there was talk of building a computer, and now I
<think that I've got a (bad, possibly) idea. In the earlier half of this
Not a bad idea but, it appears you have no technical concept of the extent
of it.
<century, transistors weren't avaible... vaccum tubes... huge ones, but
<now, the transistor has made small ones possible. My point: If we were
<to take a tubed design, and re-build it with transistors, we could
<probably make it a decent size.
< So, what da ya think?
The operating characteristics of tube and transistors are far enough apart
that circuit techniques applied to one donot apply well to the other.
The redesign would not be tivial
For most of the tube designs drum memory and mercury filled acoustic delay
lines were memory. a few used williams tubes. You would find that
difficult to duplicate.
To further make a point most of the early transistor designs were
evlotionary results of tube designs.
One of the first transistor designs was TX1 and TX2(early 50s, MIT/lincoln
labs) and theywere not small. Later ones in the 60s were PDP-1, Perkin
Elmer, CDC, to name a few and these were large as large machines(fast, big)
were the goal. The first small machines were the LINC and PDP-8.
Figure 5-10 thousand transistors and thousands of diodes, resistors,
capacitors. A foot print for a typical transistor -8 is aroung 20 square
feet plus access space.
The closest you could come and expect to complete on a singular basis would
be a to copy the archectecture of an older machine using ICs. It wouldn't
be the real thing, original peripherals would be hard to come by and there
may be a base of software if you elect to copy something like a PDP-8.
I'd do it as an engineering exercise and beacuse I happen to like certain
old archetectures. The result would not be a classic by any means.
Allison
From: Philip.Belben(a)powertech.co.uk
<So how about making our own. A tube containing, say, a 4-bit D-type
<latch? Make a few in that range and a valve computer becomes almost
<manageable! Besides, the smaller it is, the faster you can make it...
A four bit latch using valves would require not less than 8 triodes plus
buffers. Very hard to do in one envelope...
Also tubes had some characteristics that made it very hard to design fast
enough logic that distance(size) was a factor.
I have a few 7586 and 6ds4/6cw4 nuvistors and they are 0.8" tall and 0.45
dia and make really good rf amplifiers but slow switches.
Allison
<If you're going to try this, I'd suggest starting with something simple
<like an adder or a flip flop, or a register. You'd get an idea of what
<would be involved with a simple processor. But I think it would end up
<being pretty expensive.
I have some partial designs for transistor hardware. A flipflop design
used for the TX2 required 10 transistors, 22 resistors, 8 capacitors, two
inductors and three operating voltages. A register 8 bits wide would require
8 of these plus gating logic possibly doubling the number of components
needed. You can now see why early machines were register sparse.
FYI I have an article for a TIC-TAC-TOE computer using tubes and Neon lamps
and it required some nine 2d21 thyratron tubes and 190 neon lamps(serve as
gate logic mostly and two per box for display). This is a very limited
fixed logic machine and it required a lot.
Allison
HI, I'VE GOT A KAYPRO 10 AND IT'S BEEN A MILD CHALLENGE TO ENDEVOR TO
OPERATE.IF YOU COULD PART WITH THE OPERATING MANUALS I'D BE
BLESSED.THANKS BERNIE
There's a few slots up by the CPU labled MUD. I think I know what it
means. But I want to make sure. Does it mean Modified Unibus Device?
And does that mean DMA slot? And does that mean all the screwing with the
backplane I did was unneccesary?
HEATH Computer Enthusiasts:
In September I picked up a Western Union Telegraph Company Model 102
Teleprinter for our museum. It and a complete Heathkit Computer system
were the belongings of Charlie Eheman,K6ESN "K6 Every Saturday Night" of
San Diego. Charlie was a WWII Navy Chief Radioman; he passed away on August
20, 1997. His brother, Ed Eheman of Texas was in San Diego cleaning out
Charlies house.
I am looking for someone to actually put the Heathkit system to GOOD use;
in its day it was the "cat's meow." It is all in good shape with EXTENSIVE
documentation.
H9 Video display terminal
H10 Paper tape reader and perforator
H11 Digital computer (a DEC PDP11)
H14 Dot matrix printer
H19 Video display terminal
H27 Dual 8" Floppy Drive
Complete with cables and all manuals, builders notes, including the
programming courses, paper tape, 8" floppy disks, etc.
Don Robert House, N.S.E. NO JOB IS SO IMPORTANT
NADCOMM AND NO SERVICE IS SO URGENT-
3841 Reche Road THAT WE CANNOT TAKE TIME
Fallbrook, CA 92028-3810 TO PERFORM OUR WORK SAFELY.
e-mail: dhouse(a)abac.com BELL SYSTEM
http://www.hem.com/nadcomm
760-723-9959 Telephone
760-781-5161 Facsimile
ok, now that everyone's finished hashing out the 10 year rule...
I was going through some of my old junk and discovered the above mentioned
card. I need the utilities disk; i think it was called superpak or something
like that which had the clock driver, print spooler, and ramdisk setup. I
also have a copy of the super pak utilies disk user's guide if anyone wants
it. it's the first edition, as i am keeping the second edition that i also
got.
david
I would like a list of the items jrkeys(a)concentric.net
At 08:45 AM 11/19/97 +0000, you wrote:
>Found on comp.sys.tandy
>
> Greetings:
>
> I have acquired a pile of boxes from an estate sale. Numerous old
> computer pieces-parts that I thought might be of some value, but I
> don't know where to 'advertise' them -- and now they must go.
>
> Included are
> computers - TI & Radio Shack, some in perfect condition -- one is
> in a heavy steel case, RS keybd, could be home brew from misc
> parts but I can't tell, could it possibly be a stock TRS 80?
> software - cartridges & 5 1/4 floppies
> printers - are ribbons & print heads still available?
> ref books - old, specialized, probably junk
> monitors - USI, PI2, mono, unfamiliar connectors
> {also 2 non-computer antiques: 1) an old Associated Press
> linotype machine, with ribbons, very heavy. 2) 3M copier.}
> chips - small, many, stored in plastic tubes
> LNW Research products - look like large keybds but may be
> more than that -- one box is different as follows
>
> You should see this manual, it is beautiful. Yes, Virginia, there is
> such a thing as an Antique Computer. Wish it had a date in it; ref is
> made to a CA sales tax of 6%. "System Expansion for the TRS-80 [pc
> board & user manual] w/ serial RS232C / 20mA I/O
> floppy controller
> 32K bytes memory" (awesome)
> etc....
> Found a date. Guess! Answer to follow at signature.
>
> So please, somebody, send me a clue, what can I do.
> Anyone know an address where I can list these? Are old puters
> so plentiful as to not have any value as collector's items?
>
> Thanks much.
>
> ---mikey
>
> DON'T PEEK THE1ANSWER9IS8DON'T1PEEK
>
>
>
>Found on comp.sys.ti
>
>I have a couple TI99/4As, an expansion box with a disk drive and other
>stuff (very heavy), another disk drive, and some carts that a coworker
>was going to throw away. I live in Gilroy, CA and work in San Jose,
>CA. Anyone interested?
>
>Bostone1
>
>Bostone1(a)aol.com
>
>
<Speaking of Alpha's, is there any chance that I can put my own together? A
<agree... it's just plain stupid, and I hate Intel anyway... kind of like in
Sure, you can buy them used for prices that aren't all that expensive
compared to late model 486 or early p5s. The older ones are now some 4-5
years old. The OS for it will cost you. You have three choices that I
know of, OpenVMS (my favorite), Digital Unix, or NT. I don't know that
anyone has done a UNIX port outside of digital.
Allison
Hi all!
I?m afraid this computer is off-topic (dated 1988). Sorry.
An IBM 5363-I has recently been given to me, but I don?t know anything
at all about its internal architecture or capabilities. I only own the
Central Unit; no cables, no floppies, no tapes, no manuals, no
terminals.
* It has two 15-pin sub-d connectors in one expansion card. They seem to
be for attaching two serial terminals (syncronous? type 5250?)
* In another expansion board it has a 9-pin sub-d connector.
* There are too four twin-axial connectors.
Can anybody help me on this subject?
Thanks in advance.
--
Sergio Izquierdo Garcia
mailto:henrio@edu.tsai.es