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Tektronix 'Board Bucket' 6800

falter

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Jan 22, 2011
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Vancouver, BC
Not sure yet but it's looking like my SWTPC 6800 purchase is going off the rails. More details on that later. I also sold some stuff, and as a consolation prize jumped in last second for this:

http://www.ebay.ca/itm/Vintage-1970...287175?hash=item2a6c668f87:g:s08AAOSw0fhXiYJ5

I've no idea what the deal with this is. I was intrigued by the copyright date on the boards, and the age of most of the ICs, some going back as far as the late 60s. I'm guessing it's a 1975-ish system with some later boards and replacement ICs, but who knows. The seller apparently had it checked out by their museum (they have a museum?) and they thought it might have been a development system used for one of their terminals or even the 4051 computer they did. She got it from the estate of one of their engineers.

Just thought it was kind of neat, and though I'd put it here in case others have seen anything like it or have ideas on what it might actually be.
 
Looks like a great get.

I note the number of pins/pads on board edge are 36 on side that visible making it 72 way. So certainly different to S100 or Motorola 86 way board edges.

On the board with the 6 red segment displays, I think i can make out the words data above the rh pair and address above the LH four of the displays. Be very interesting to know part number on there red displays. I am thinking they are Alpha numeric ones and will give you system address and matching data in Hex.

Looking at the first eBay photo, I see this board is first in the cage. You could consider cutting a very neat slot in front case and put a display bezel in so you can view the displays from front. Just a thought.

Again great get.

top view.jpg
 
Thanks!! I didn't think much of it at first but I just kept looking at it and thinking - wow... this is kind of neat.

I can't find any pics of the insides of a 4051 yet with google but I'd love to know if the 4051 had boards like these. I can't find anything online about the board part numbers, etc. It'd be really cool if it was used to develop their graphics terminals, or the 4051. Or if it *is* a 4051 in sort of proto-development form.

Speaking of the 4051.. one sold on Ebay recently: http://www.ebay.ca/itm/1976-Tektron...515059?hash=item3d18e2b273:g:DvIAAOSwn1RXImxJ

$399! Darn!

I didn't know anything about Tektronix, but watching the 4051 in this video in action has me badly wanting one:

https://www.youtube.com/watch?v=9yCHW0tQrAA

Mmm storage tube display.

I'm hoping that this thing isn't specifically requiring a Tektronix graphics terminal to operate. That would put a crimp in things. I don't quite understand how graphics terminals operate vs. ASCII text terminals.

I agree it'd be nice to see those lights. I wonder if the front panel could come off entirely (to spare cutting it) and just put plexiglass or something up instead.
 
I have a 4051 if wanted, search for my other post.

It has one large logic board in the bottom plus a side board with the CRT circuitry on it, the expansion RAM is a separate board above the logic board.
 
Hum, couldn't find it either, sure I listed it for sale possibly a year or two ago. I was getting it going and a poor soldered joint on a transistor I removed to test resulted in an EHT flashover, gave up at that point. It was displaying characters on the screen as typed, but not storing them, one of the CRT electrode voltages was low, hence testing the transistor. Had already replaced a few caps and other transistors.

It is huge and heavy, not really a postable item, I can only just lift it.
 
Yeah and you're in the UK.. wonder how the shipping/freight would compare vs. the US, which has gotten surprisingly expensive. You guys have 220v power right? Is that how it's set up? I think it's a fascinating machine. I'd pay whatever, within reason for one I think. Wish I hadn't missed that ebay one.
 
Just guessing weight, 35kg, and size, 80x50x50cm, comes up with a delivery cost of about 130GBP, plus quite a bit of packing costs. To be honest you really want to find one as close as possible.
 
mmm maybe if as I commented to woodchip in my Analog Computer post on VCFed, I come to UK after Germany, and Falter you so want it, I might be convinced to pack it in accompanied luggage and head via Vancover on way back to Australia.

Seriously though I doubt it would fit in a reasonable suitcase, by time you added enough padding packing. so probably not most suitable way. Sorry Falter, and just realized I think 25kg is the limit for each accompanied bags on aircraft.

regards
David
 
$130GBP is $230cad roughly. Are you sure? Thats not as bad as you think. To ship my Tektronix box via USPS was close to $175CAD, and that's just from next door USA. It's just how it is. Where I live.. this kind of thing never pops up for sale locally.

It's a function of what your asking price is though.

And I appreciate the thought David! Probably they'd suspect you of bringing a bomb! :)
 
And a few more.

20160804_090831.jpg

20160804_090835.jpg

20160804_090855.jpg

20160804_090901.jpg

Now, unfortunately we might have had a mishap.. I plugged the unit in not realizing that that little board at the back (think it's voltage regulation) had fallen off. I don't think anything bad happened but the machine would not turn on (hopefully as designed). I found the board loose in the case and plugged it in. That gets us this:

https://www.youtube.com/watch?v=7YSUuF6xTAg

It's hard to see with my camera.. but the display when reset isn't pressed isn't quite clear.. some of the led segments look partly filled in. I tried hitting the little Step button but nothing happens.

There's nothing happening on the serial ports.. I note they say 'DCE' on the back.. I'm assuming a null modem is good enough.

Could be quite a challenge getting this thing working. I'm going to try contacting Tektronix and see if they can find anything out about it.
 
It works!

Many thanks to former Tektronix engineer Rick Bensene.. it turns out my main problem with this 6800 unit was the cable I was using (again!).

Works like a champ now! And according to Rick the BASIC in ROM is quite rare.. usually these machines used a developer oriented monitor called DDT, which can be seen in the first prompt. Rick thinks it may have been the BASIC they developed for the 4051.

https://drive.google.com/file/d/0B4pq0-BHd2x6dmxYYUFqSFF1WEE/view?usp=drivesdk
 
It works!

Many thanks to former Tektronix engineer Rick Bensene.. it turns out my main problem with this 6800 unit was the cable I was using (again!).

Works like a champ now! And according to Rick the BASIC in ROM is quite rare.. usually these machines used a developer oriented monitor called DDT, which can be seen in the first prompt. Rick thinks it may have been the BASIC they developed for the 4051.

https://drive.google.com/file/d/0B4pq0-BHd2x6dmxYYUFqSFF1WEE/view?usp=drivesdk

Hi there,

I have to say any Tektronix engineers I had the need to deal with over the last 40 years, have always been EXCEPTIONALLY helpful and very professional.

Falter, since Rick says this Basic in ROM is quite rare, I humbly suggest you discuss with him the best way to copy it and place the image in bitsavers. I am sure Rick would love a copy.


NOT wishing to tell you how to suck dinosaur eggs, but I have seen more than my fair share of people putting a working rare ROM/Eprom in a reader/burner, only to either put it in backwards and fry it, or off-setting a 24pin chip in the programmers dual use 24/28pin socket at the wrong end, or corrupt it by selecting the wrong command in their reader/programmer software.

Hopefully its not read protected.

Having an original Motorola 6800 system, I would be quite interested to get a chance to try a copy of this BASIC for my machine.
 
For sure.. I don't even have a ROM reader so it'll be a while. I do not like not having a backup of some kind and definitely would like to share it out there. So I'll have to get one asap.

Rick was fantastic. He even knew who owned this machine from the engineer's initials. Seems like a really great company, or was. It's funny.. every now and again I think ok.. I've collected everything worth collecting and then along comes some 'new' thing like the 4051 that is so unique from everything else. This hobby is ever expanding!

There isn't a way to get BASIC to tell you what version/whose it is is there?
 
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Actually absolute limit is usually 32kg for health and safety ... I still fancy that Tecfor myself but just not been in the UK long enough to pay Woodchips another visit. Perhaps november. (in spain now, USA & Canada September, October recover from Jet Lag)...
 
Falter, since Rick says this Basic in ROM is quite rare, I humbly suggest you discuss with him the best way to copy it and place the image in bitsavers. I am sure Rick would love a copy.

yes, I was just about to ask about this.
it would be fun to get this running in MAME

--

also, it should be possible to just capture it using memory dump in the debugger
 
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He even knew who owned this machine from the engineer's initials.

Must have been an interesting guy.. I've bought some other things, like a compete Pascal Microengine with all the software, which Eric Smith and
I had been trying to find for a couple decades on eBay that came from the same seller.
 
Very cool! Thought about grabbing this one myself, but decided I've got too many other projects on the table as-is!

Since you seem to be running in to a lot of RS-232 cable headaches, I'd recommend you pick up a Smart Cable. I've got this particular model:

https://www.smart-cable.com/catalog?action=display&key=102

They show up on eBay sorta often for a lot less than the brand-new asking price. It's like a light box you can reconfigure with just switches, and the little manual that comes with it goes through common issues and how to diagnose/correct them using the switches and lights on the box.
 
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