| Posted By
Gaia
on 2007-03-27
06:30:47
|  Unknown TED machine?
There has been a very interesting post on the cbm hackers list from Anders Carlsson. He has gotten hold of an unknown TED based motherboard. I copy the complete message over here maybe someone might have a clue. I presume from the ceramic chips that it is a some sort of a prototype board.
"
I have come across an unknown, TED based motherboard which I would appreciate pointers about. It only has 14 chips, named as following:
U1 = NE555N 8144
U2 = P8214A DM7406N
U3 = U4LS139N 8137 SA
U4 = empty
U5 = INMOS 8329-A IMS 2629P-15 C1059A KOREA
U6 = INMOS 8329-A IMS 2629P-15 C1065A KOREA
U7 = 74LS257AN 8216 SA
U8 = ?? (unnamed logic chip, perhaps CPU?)
U9 = empty
U10 = 27128 EPROM marked "TED LO"
U11 = 2764 EPROM marked "TED HI LO-V1.0"
U12 = 2764 EPROM marked "TED HI HI"
U13 = 74LS257AN 8216 SA
U14 = MOS 7360R4A 4183 (TED)
Low resolution image at: http://www.cbm.sfks.se/pics/tedmb.jpg
I can upload a higher resolution image at a later time.
Where is the 7501/8501 CPU, is that the unnamed one in U8? As you can see, there are two diodes running between some pins on the TED chip, and some extra (cut?) wire near the cartridge port. Later I can look up exactly which pins the diodes go between.
On the under side of this motherboard, it is stamped "Q.C INSP'D AUG 3 1983". Is this normal for an early TED line motherboard, given that they started to sell sometime during 1984 if I recall correctly? I was thinking maybe this is some prototype.
I tried to power it up, despite lacking some chips. It makes a faint buzzing noise. Using a video cable, the monitor detects power on, but no picture. Using RF, there is no signal at all, at least not at UHF 36. I noticed the RF modulator has a small switch, which suggests it may be a NTSC unit rather than PAL?
I see that Zimmers have some schematics for different Plus/4, Commodore 16 and 116. Which one would best match this board, and how can I find out which chips should go into U4 (logic gate?) and U8 ? Probably it'd be tricky to get working anyway, given that fully equipped Plus/4 tend to break in CPU and TED chips, much less a loose board that for some reason has been sitting on a shelf for 15-20 years.
"
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Posted By
TLC
on 2007-03-27
06:59:15
| Re: Unknown TED machine?
This must be some kind of a development board, judging from the kind of connectors, the ceramic TED (anyone ever seen such an early TED?... ) and others... Anders must have found something very rare and interesing...
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Posted By
Sidius
on 2007-03-27
07:12:06
 | Re: Unknown TED machine?
Hmmm, it looks like a prototype or a "test-board"...
...such a thing I've never seen before !
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Posted By
JamesC
on 2007-03-27
07:44:10
| Re: Unknown TED machine?
I agree .... it's a prototype board. Note the layout and type of connectors. This is the arrangement of a C64 motherboard.
Adding to this, the marking "P19" on the left, near the datassette connector, is probably "Prototype 19". One working V364 was shown at CES in January 1984 - the date code of Week 41, 1983 on TED would be September 1983.
Personally, I think it's amazing that Commodore could go from this board (I would date it October to November 1983) to the motherboard in Zimmer's V364 (December 1983 to January 1984, shown on Bo's website) in such a short amount of time.
And since the design changed so radically in that short time, I wouldn't expect this board to work at all.
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Posted By
Gaia
on 2007-03-27
08:01:22
| Re: Unknown TED machine?
Has someone read the book "The spectacular rise and fall of Commodore"? I did  Bil Herd states in that book that the engineers initially used a "castrated" VIC-II chip and a C64 motherboard for the 264 series. Although I think that in this case we are having a "genuine" TED chip already (note the revision number, it's the 4th revision!), the only TED chip documentation we have is for the 7360R0, so this chip revision must be of later than that...
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Posted By
Chicken
on 2007-03-27
13:10:44
 | Re: Unknown TED machine?
Though a bit off topic, would you recommend that book? I was thinking about ordering it but most books I have read so far about "home computers" were badly researched, just scratching the surface with (inaccurate) facts that you can find on every other website.
Furthermore, these books are sometimes extremely bad written and it shows, that the authors (even if they are interested in the subject matter) are not "writers".
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Posted By
Bionic
on 2007-03-27
14:42:58
| Re: Unknown TED machine?
I can recommend that book. Some minor errors, but generally written quite well. Not amateurish.
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Posted By
Gaia
on 2007-03-27
18:00:11
| Re: Unknown TED machine?
Me likes it too. A couple of inaccuracies that's all. It has been written with passion and it shows.
Anyway, right off the wire here's some news from Mr Herd himself about the mysterious photograph:
"At first I thought it was a C64CR type
thing but this looks like a member of the TED family, probably a C16. It
has the standard joystick ports so its one of the later strange things like
the C16 that magically appeared. The two resistors on the chip mark it as a
TED where the test mode pins were higher impedance than predicted by the
chip designers and a strong electric field would freeze the counters. The
diodes near the keyboard connector also make it a TED, though there is a
chip missing from my last rev of it, this may be a non-production board (in
fact none with the resistors would have made the airwaves). Since there are
only two chips that look like memory, it is probably 16Mb.
...
Clearly a TED, the unnamed 40pin chip is something like
a 7501 cpu which is a processor with a gated r/w line to hold the line valid
through the DRAM cycle. I added U1 myself as the design when I got to CBM
tried to use the 7406 as a level detecting reset circuit.
The design also called for the data lines to go directly out the keyboard
port (hence diodes, Germanium no less, to keep the data lines from shorting
out when you pressed multiple keys) which was also the joystick port. the
problem was the noise the joystick port would pick up would create sparkles
in the picture due to blown data. I added an 8 bit latch (nmos MOS 8529 or
something like that) to isolate the data lines form the keyboard/joystick.
"
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Posted By
Carlsson
on 2007-03-28
18:12:10
| Re: Unknown TED machine?
Hi.
I'm Anders. If you want to see higher resolution pictures, try these URLs:
1 2 3 4
Feel free to copy the images, but please do not deep link them into e.g. a forum, blog or otherwise (to save me unneccessary bandwidth leeching).
As soon as I receive my EPROM burner, I will carefully remove those EPROMs and dump them for the world. Whether or not this board can be made to work.. well, at least two chips are missing, and we don't know if this early TED with extra diodes/resistors is any more fault tolerant than the production units. Ditto for the CPU.
[edited by Luca: our own links used]
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Posted By
Luca
on 2007-03-28
18:15:28
 | Re: Unknown TED machine?
Be careful Anders! 
And congrats for the discovery!
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Posted By
Gaia
on 2007-03-28
18:50:57
| Re: Unknown TED machine?
Beautiful, especially the TED Thanks Anders. Where did you get this from??
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Posted By
SVS
on 2007-03-29
02:40:41
 | Re: Unknown TED machine?
The note "PI9" handy written, could be read as "bid" if you turn over the image. Could this mean something?
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Posted By
Carlsson
on 2007-03-29
03:16:02
| Re: Unknown TED machine?
Haha, subliminary messages written directly onto the board. Maybe manufacturers of today should put BUY ME! on the box to attract customers.
I picked up this board from a retired PET/CBM reseller, who also had a small side business in software development. As per Bil Herd, this may be an early board sent to developers around the world to prepare TED line software before the launch.
It spurs the discussion when Plus/4 was officially available. In the US, it did not seem to appear until October 1984, and probably true for most part of Europe too. In Canada however, there are indications that Plus/4 was available already in February 1984, and some sources claim other TED based machines were for sale already at Christmas 1983, which is odd as Commodore presented the 264 and 364 on CES in January 1984...
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Posted By
Luca
on 2007-03-29
03:36:30
| Re: Unknown TED machine?
WTF Csabo, do you hear what Anders says? Will you stay at home or will you try to go hunting?
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Posted By
Gaia
on 2007-03-30
05:00:09
| Re: Unknown TED machine?
Bil Herd said it is his own handwriting on the prototype board
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Posted By
Carlsson
on 2007-04-04
02:29:13
| Re: Unknown TED machine?
Now I have tried to dump the EPROMs, with more or less success. The data may be garbled, but at least I believe it is consistant from reading the chip many times. As posted on the cbm-hackers mailing list, you can download the raw binary dumps here:
http://www.cbm.sfks.se/files/ted-eproms.zip
As per William Levak, ted-lo.bin probably goes into $8000-$BFFF, ted-hilo.bin into $C000-$DFFF and ted-hihi.bin into $E000-$FFFF. I don't have a clue if they practically usable on any "modern" TED based computer, even without the possible addition of garbage.
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Posted By
MasK
on 2007-04-11
15:58:01
| Re: Unknown TED machine?
Coool
Ted-hilo and ted-hihi is working now as a kernal in my vice
Giving a "Break PC 00 00 00 00 00 FF" prompt,just can't type because modern +4 style keyboard emulation.
But I can see in vice's debugger,the rom code is working correctly,waiting for old "ted style" keyboard's keypresses..:D
This panel should be a working board I think,the rom-code is initialising the Ted correctly,and doing all functions for monitor at least.
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