2 datapath boards I was missing for the 785, almost the rest of the 780
(Missing only one board! The microsequencer... [M8235]...)
Interesting toys include:
A DZV11. Does anyone have the pinout for the distribution panel for this?
And a SUMMUS 422-U controller.
It has a SCSI-style plug at the top, it's a quad-height ?bus controller,
and I'm told it wants a SCSI tape drive attached to it.
The main chip says "442/UDT 4641" on top. A ROM is on here, it says
"Viking U/B A4.4"
Any info on this?
I remember back in the soviet union there were a couple of good
magazines for young people that had projects in them.I was too young
to build any of them, and you'd have a hard time getting a blank
PCB there anyway, but they had a primitive rover-like robot (with
programmable modules based on the arrangement of electrical traces
on a cartridge), an RC boat, etc. I'd love to get my hands on one
of those. When I go back there (hopefully in a couple of years), I
will be sure to photocopy some of the stuff. Nothing like "build 99
projects" of today.
>> It's no loss IMO. Byte hasn't been worth the paper it was printed
>Agreed. I stopped reading Byte shortly after the last 'Ciarcia's
>Cellar'. It's not that that was the only interesting article in it -
>of the programming articles were great as well. But all the good stuff
>went at about the same time, and Byte became yet another ready-built
>> for a looonnggg time. The same thing happened to Popular
>> another of good OLD magazines.
>Are there _any_ good electronics/computer mags left now (especially in
>the UK)? Elektor used to be good, but recently it's all been
>pre-programmed PLDs with no idea as to what's in them, controlled by
>binary-only software for Microsoft OS's. No interest there for me...
Get Your Private, Free Email at http://www.hotmail.com
I emailed IBM. they said they transferred the stuff to someplace
called Greenleaf computers (I think, not sure). I didn't bother to
pursue it. They will be happy to give you the phone #.
>> Are technical references for IBM XT's / 286 machines avaialbe from
>> still? If so then I assume that they charge quite a bit of money for
>AFAIK, all are out of print, but IBM probably have some remaining stock
>of most of them. I bought several manuals about a year ago.
>The XT Model 286 manual is unavailable.
>The others that you might need are :
>XT and Portable PC
>AT suplement for the type 2 board
>(those contain schematics of the motherboard and keyboard, BIOS
>Options and Adapters. 2 volumes covering just about every card for the
>and XT, monitors, drives, etc.
>O&A AT update (16 bit cards, serial/parallel adapter, etc)
>Scientific O&A (GPIB, DAC, PGC, etc)
>PC-jr (PC-jr motherboard _and all option cards_ for it in one manual)
>I posted the forms numbers (which you need to get them from IBM) on
>list a few months back - it's probably in the archives somewhere...
>They're not cheap, but not too expensive IMHO. Figure on \pounds 50.00
>per volume. I was pleasantly supprised by the ammount of information
Get Your Private, Free Email at http://www.hotmail.com
I don't know if everyone has heard, but the July issue of Byte will be the
last issue. It's a sad day for the computer industry. While Byte has
become primarily a Windows magazine in the past few years, they were still
the closest thing to a general purpose magazine left, and the only
non-specialized computer magazine that I still bought.
The following C/Net article gives the details
| Zane H. Healy | UNIX Systems Adminstrator |
| healyzh(a)ix.netcom.com (primary) | Linux Enthusiast |
| healyzh(a)holonet.net (alternate) | Classic Computer Collector |
| For Empire of the Petal Throne and Traveller Role Playing, |
| see http://www.dragonfire.net/~healyzh/ |
| For the collecting of Classic Computers with info on them. |
| see http://www.dragonfire.net/~healyzh/museum.html |
<Is there a socketed PLCC chip in the middle of the board? (the so-called
<GIME chip). If so, it's a 3.
Yes there is.
<The disk controller is basically a WD1773 + support circuitry. And a ROM
<containing the disk extensions to basic. Not trivial to build, but not
<impossible. You might find a second hand one somewhere.
The FDC is easy as I have 1793 and 8229(glue chip). The rom is a show
stopper. I'll have to keep an eye open.
On May 29, 6:53, Joe wrote:
> Cord wrote:
> >I just picked up an older style laptop that I need some hlp on. It is
> >a Toshiba T2200SX laptop.
> >1) I need a battery for this unit. I have the power supply, but the
> >battery with it won't charge.
> Your chances of finding another battery are slim. Even if you find one
> it will be old and probably won't last long. My suggestion is to take it
> to one of the battery places that rebuild batteries and have them replace
> the cells in your old battery.
If you can take the battery pack apart (separate it into single cells) in
such a way that it could be re-assembled, all is not lost.
The usual problem with NiCds is that internal crystal growth makes short
circuits; the battery will show virtually 0V. If you force a sufficiently
high current through the cell, it will often remove the short. However,
the current needs to be very high, and has to be of short duration to avoid
The way I do it, is to charge a large electrolytic capacitor up to 20V -
30V, connect one side to one end of a cell with a short thick wire, and
touch ("flash") the other side to the other end with another short thick
wire. The spark is usually fairly dramatic, so it's best to touch the wire
to the terminals and not the case (lest the arc burn through it), and use
eye protection. Repeat as required until the cell shows some reasonable
Then put the cell through a full-charge/deep-discharge/full-charge cycle.
I've resurrected quite a few NiCds with my 24V bench PSU and a 50,000mfd
BTW, inside a lot of laptop batteries, you'll find a small metal box in
series with the cells. Don't throw it away; it's a thermal cutout intended
to prevent excessive current flow.
Pete Peter Turnbull
Dept. of Computer Science
University of York
Are technical references for IBM XT's / 286 machines avaialbe from IBM
still? If so then I assume that they charge quite a bit of money for
If you can't get them any longer, then has anyone scanned any of the
information and stuck it on the 'net anywhere? (Schematics are one
thing, I remember downloading lots of info on various things such as DMA
controller specs etc. a few years ago, and theamount of conflicting
information out there made it rather difficult to get anywhere!! :)
I first discovered digital logic and TTL IC's about 1973, and wanted to
build something not trivial with them. The project I chose was John Conway's
game of "life" as described in Martin Gardner's Mathematical Games in
I ending using a 32x32 element grid using 2 (then expensive!) 2102 rams (No
A or other suffix then) I would calculate one generation from one ram and
write to the other. I used about a 60kHz clock and 74193 counters to
generate the addresses. The clock went to a decade counter and the first 8
states generated +/- x and y clocks to visit the 8 neighbors of a given
cell. If the cell was a "1", another counter was incremented, number of
neighbors. The 9'th state was at the given cell.
The rule was then used: Neighbors =2 and cell active, or Neighbors = 3, then
the new cell was active, otherwise it was not. The 10'th clock wrote the
cell to the new generation (the other ram). Thus 10 clock cycles were needed
for each cell, or 10240 for each generation. This was much faster than a
later 4MHz Z-80 program!
I displayed the results on a 5 inch oscilloscope, using 555 timers with PNP
transistor current sources to charge the timing capacitor, for x and y ramp
or deflection waveforms. This was straight out of a National Semiconductor
databook. The refresh rate was about 60Hz. The "load" signals for the
74193's was used to write data into locations from address switches. Finally
3 7490's and 7447's displayed the generation number on 7 segment displays.
It was fun to watch the generations flash by. The total number of IC's was
about 35 + 6 for the generation counter.
From: Tony Duell <ard(a)p850ug1.demon.co.uk>
To: Discussion re-collecting of classic computers
Date: Thursday, May 28, 1998 8:31
Subject: Re: Original IBM PC (was Re: Prices to pay for old
>> oh well with my 5150 it has two FH IBM drives in i and they both seem to
>> dead, Ive replaced the controllor card check the dips,
>> checked power output, it seems here in Austrlaia these drives are almost
>> impossable to get a hold of......
>I have schematics for these drives (in the IBM O&A TechRef) and the Tandy
>instructions for aligning the single-sided version. So I think we can get
>You say they're 'dead'. How dead? Why you access them, does the motor
>start. Does the spindle rotate? Does the head carriage move to track 0
>when you first boot up the machine (turn off, move the head towards the
>spindle, turn on). Does the LED come on?
>Or do they seem to work, and go through all the motions, but give you
Apple Lisa Web Page:
I get nothing out of them, no motor spin up, no led, no