At 21:44 20/06/97 +0100, we wrote:
>>
>>>Besides, I was talking about CP/M for the Commodore 1541 drive. That's a
>>>multi-speed drive that uses GCR encoding, not MFM. Try writing THAT with
>>>22DISK on your PC-clone.
>>>I used to know that only C=1570 and C=1571 were capable to read and write
>>CP/M disks in a proper way. (GCR+MFM)
>>By the way anyone else apart me owning a C=1570 here?
>>
>>Ciao
>>
>>i own a 1570, its a american one with a step down transformer, Its
>connected to my PC, and guess what, it writes CPM!!!
>Steve
>Emulator BBS
>01284 760851
>Keeping 8-Bit ALIVE
Hi Steve,
Yours was the only one response I get (since now) from C=1570 owners
Mine was made in Germany (did you buy it in the U.S.?)
Ciao
A place in my location called surplus exchange, has about a dozen pcJR's on
a skid. I didn't find any power supplies, but by the looks of the place,
they could be anywhere. Let me know what to look for when I go back and
I'll see if I can't rescue some more. (assuming the old lady lets me). I
know the PC JR I bought, has a Parallell port on the outside, which I
learned only today is a "Side-car". I have dozens of composite mono and
color monitors from my apple// and Zenith collections. I also managed to
scrounge out of this pile, [one] keyboard with cable, and [one] joystick
and about 5 or 6 cartridges. The other PCjr,s seemed to be alone. Let me
know what to look for on the CPU's and I can go through all of them one by
one. If anyone else want's one, let me know and we can see what we can do.
Last trip there I got a TI99/4a, atari 800, 1050 drive, 410 drive, Tandy
COCO 1,. Commodore 1741 drive, Commodore mps 803 printer (I think) it works
good. And an apple//+ for parts. I paid 35 for everything. I noticed this
pallete of Jr's but I sure as heck didn't see any monitors, keyboards or
power, except the one keyboard I did find elsewhere in the building.
----------
> From: jpero(a)mail.cgo.wave.ca
> To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
> Subject: Re: IBM PCjr
> Date: Monday, June 23, 1997 9:28 AM
>
>
> > Welp, that rules out rigging one, thats beyond my techincal ability to
> > fabricate. Anyone have an Extra for sale or trade?
> They're underrated but you can just get one to keep orginals but I
> could supply you a adapter for your own use with a PC power supply
> box. This way, you can simply plug in and go?
>
> I do not know where to get these black transformer bricks. The
> PCjr around here is rare as hen's teeth in my hometown. :)
> Considering that, I was lucky to find it in standard configuration of
> parallel port side car and the box but no cartidges! :(
>
> I also overheard that someone was trying to use TV with PCjr, you
> missed something really needed: demodulator box or find a computer
> compsite monitor which works better especially in 80 column mode.
> Commorde color monitors is good picks for this.
>
> Jason D.
but *not* from me! Read carefully!
Forwarded from comp.apple2.marketplace
--- Begin forwarded message ---
Date: Mon, 23 Jun 1997 05:22:35 -0600
From: HartranftR(a)nabisco.com
Newsgroups: comp.sys.apple2.marketplace
Subject: Apple III's for sale
FYI ... I have 5 Apple ///'s for sale (improved re-release
version), including original monitors. Some with 512K memory. Some
peripherals also, including spare parts, Corvus 20 meg server with
related Apple III interface cards. Would prefer selling at least
computers/monitors in bulk and will consider any reasonable offers. I
understand there are now thriving museums and actual user groups still
utilizing. If NOT interested, would appreciate any leads for other
possible contacts. These machines actually served us quite well !
Thanks
Rich H
-------------------==== Posted via Deja News ====-----------------------
http://www.dejanews.com/ Search, Read, Post to Usenet
--- end of forwarded message ---
-jim
---
jimw(a)agora.rdrop.com
The Computer Garage - http://www.rdrop.com/~jimw
Computer Garage Fax - (503) 646-0174
Okay, I asked a simple question. Got 3 differnt answers, and folks
referring to "over here" and whatever.
I live in the US, I will need to go to radio shack to build this.
Which diagram is the safest, what parts do I need, and what do I do.
----------
> From: jpero(a)mail.cgo.wave.ca
> To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
> Subject: Re: IBM PCjr Allright?????
> Date: Monday, June 23, 1997 12:27 PM
>
>
> > Yes, I've seen that convention. But if you buy a transformer over here,
> > the connection tags will be labelled 0V and 17V or whatever. I've never
> > seen a physical transformer marked with a dot (that's not to say they
> > don't exist).
> Yeah, nothing marked to tell us of phases. :) So that invites
> mistakes by unwary who makes power supplies on their own. That why I
> offered warning. :)
>
> (hey, my power supply did not work...) eyes up. :)
>
> Jason D.
What am I making here? Do we know yet?
----------
> From: jpero(a)mail.cgo.wave.ca
> To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
> Subject: Re: IBM PCjr
> Date: Monday, June 23, 1997 9:51 AM
>
> Hello Tony,
> >
> > >From memory the central pin is chassis ground and the outside 2 are
18V AC
> > at about 3A.
> Actually 34vac 2amp center tapped transformer. The center tap goes
> to ground, what else how can negative voltages can be generated so
> it needs this ground. The both outside 2 pins for 17v ac lines goes
> there. The card rectify it to generate 3 dc voltages, two is
> positive and other one is negative. Bulk of the components is used
> to generate 5vdc, and a wimpy 12vdc source for the floppy drive and
> fan. And last one is in very small current negative current -12v dc
> which takes this voltage and go through a 7905 regulator to get -5v
> dc, both voltages are strictly for serial use and little use for
> else.
>
> Funny, instead of 60hz, you get the same type of circuit design in
> secondary side in lots of switching power supplies with few minor
> differences.
>
> The limits to overdrive if you do, both card and slot is due to the
> current limit allowance per contact on that slot. :( Leave it to be
> and parallel the seperate power sources to the sidecars if they have
> them. Another problem with this is that 3 connections is not enough
> to carry more than 2amp on each socket.
>
> By the way, I am Electomechanical major in training "on hold". :)
>
> > The manual doesn't give the schematics of the transformer unit (it does
> > for the PSU card in the main unit), and it's not clear from the
> > description whether the AC input is centre-tapped to ground or not.
> > Looking at the schematics, I think that it is _NOT_
>
> Oh yes, I did saw the techref for the outside PSU transformer is
> pretty simple just a disconnectable center tapped transformer.
> One thing I hated that they did not give us the that schematics for
> that power card module which I revsere engineered instead!
>
> Jason D.
The Color Computers were:
Color Computer 1: Silver/black, 4K-64K
Color Computer 2: White, 4K-64K
Color Computer 3: White, 64K-128K
Micro Color Computer: White, tiny, 4K
I've never heard of a TDP-100. The Color Computers had ROM BASIC and
most serious users ran an operating system called OS-9 which was kind of
like TopView.
Expansion is via the cartridge slot. The floppy disk interface was
implemented as a cartridge, with the floppy OS in ROM in the controller
cartridge. CoCo floppy drives are rare. Floppies stored 156K. There
was also a hard disk cartridge, believe it or not; plus, a Multi-Pak
Interface which allowed you to connect four different carts and switch
between them.
There are lots of CoCo fanatics around, somebody probably sells parts
and maybe even schematics.
In regard to the Inboard/386, as I recall it had 1MB 32-bit RAM on the
card, and could optionally use motherboard RAM which of course ran at a
much slower rate. My memories may be confused with the Inboard/386 AT,
but I seem to remember a daughtercard which could store an additional
2MB or so. Good luck finding a daughtercard though.
Kai
> ----------
> From: allisonp@world.std.com[SMTP:allisonp@world.std.com]
> Reply To: classiccmp(a)u.washington.edu
> Sent: Tuesday, June 10, 1997 11:01 AM
> To: Discussion re-collecting of classic computers
> Subject: cocos and stuff
>
> HI,
>
> In my non-op list of equipment I have three cocos apparently
> operational.
> They are of two different styles.
>
> The smaller is the TRS80 color computer with real keys on the
> keyboard.
> I have two of these one the case was wiped out, board is ok.
>
> The larger is TDP-100 personal color computer with chiclet keys.
>
> Lacking docs I presume these have rom Basic. What expansion is
> possible
> (there is a port) and how hard. Do they run any real OSs or some
> TRShack?
>
> What's the odds of finding DOCS especially schematics?
>
>
> I have a xt class machine with an Intel Inboard386...(works too!)
> what's the
> odds of finding schemtics or expansion ram for it? The 1meg of ram is
> tight
> for somne stuff. Currently I use it as a 10x faster xt.
>
> Allison
>
> %I've been looking for a Jupiter Ace for over 10 years! Do you have any
> %leads on them?
The schematics were printed in The Computer Journal last year sometime.
IIRC, The Computer Journal's URL is http://www.psyber.com/~tcj/.
> I have a jupiter ace. It's sitting is a closet somewhere back in
> Singapore.
>
> Another sign of the folly of my youth :
I have a Jupiter Ace hanging around, also. However, I just built it
last year. Unfortunately, I had to give the rubber keyboard and most of the
memory back to the fellow I borrowed them from; I haven't yet gotten around to
building a keyboard from aluminized mylar, cardboard, and Tyvek (this should
give me a working keyboard, but it will be of ZX80 quality). I've also found
enough 2114s in an old MDA card to bring my Ace back to life...
> the machine is stripped out,
> the TV modulator is missing
I don't have a modulator in mine. I gummed a 15-pin D connector to it so I
could drive a spare DEC VR201 I had lying around (yes, the VR201 apparently
does have enough range to do PAL; it worked great).
Roger Ivie
ivie(a)cc.usu.edu
Actually, I believe that Hot Coco was a mag published by Wayne Green of 80-Micro and Byte fame.
Regards,
Bob
----------
From: Mike Sprague[SMTP:sprague@VivaNET.com]
Sent: Sunday, June 22, 1997 9:40 AM
To: Discussion re-collecting of classic computers
Subject: Re: Cocos
e.tedeschi wrote:
>
> Just to help me understand better...when you refer to Cocos, do you
> refer to the Tandy TRS-80 COlour COmputers?
Yes. I don't know where the name origionally started, but the support
magazine Tandy put out was called Hot CoCo.
~ Mike
You aren't the only one who does old PC's...that's my business (I
recondition old XT/AT's and sell them. Send strange questions to me.
I also still sell an occasional Commodore piece!
> My main interests (although I enjoy reading all of this) is the older
> systems based on the IBM-PC (XT & AT class) machines and PS/2s which I
> know is a bit more current than many of you like. I also have a
> Commodore 64 and Plus/4 and periphs, I guess I can qualify based on
> that.
"A.R. Duell" <ard12(a)eng.cam.ac.uk> writes:
> I've never liked bit-banged serial ports either (except on
> microcontrollers). They always seem to have problems with full-duplex
> operation. Yes, Apple sold a bit-banged serial port for a time - I have
> one with the manual (which, amazingly contains instructions on linking it
> to an ASR33), presumably to save a UART chip. They then sold one that
> worked properly (in full-duplex mode, etc) under the name 'super serial
> card'. It used (IIRC) a 6850 chip (or was it a 6551?)
Hmm? What was that bit-banged serial port?
If you look in the Apple ][ red book, there is a little circuit
in there that plugs into the game I/O connector and drives a
20mA current loop. Alongside there is a short assembly program
to drive it. Now there is a bit-banger.
There was an unspectacular serial card for the ][. I don't recall it
being a bit banger, just that the combination of it and the printer I
was using at the time (an IDS BrighterWriter) wasn't smart enough to
manage any sort of common flow control, so that I had to run it at 300
baud. I thought it had some sort of UART-like thing, but maybe my
brain is going again.
Hmm, I think it was called the Asynchronous Serial Interface or
something like that. There was also a Synchronous Serial Interface
that (I recently found out) was the Silentype printer interface.
I don't remember the Mountain Hardware CPS card that well, and I feel
very good about that based on what I do remember. Now there was a
klu[d]ge.
The Apple Super Serial Card was designed around a 6551.
There were a couple of other cards designed around the 6850.
The Hayes Micromodem ][ was one of these.
...
Strange as it seems today (now that I have done some programming
around PC-contemptible serial ports), the Apple ][ serial cards and
software generally worked by software-polling-hardware. The only
serial card I can remember supporting interrupts was the Super Serial
Card, and I can't say that I ever saw it used that way. Certainly
none of the "standard" software required it; interrupts just weren't
generally done on Apple ][s.
-Frank McConnell
