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Vintage Computers Any vintage computer systems, calculators, video games etc., but with an emphasis on 1980s and earlier equipment.

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Old 9th Apr 2021, 6:17 pm   #1481
ajgriff
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Default Re: Non-working Commodore PET 3016

Wow! I'm very impressed.

Alan
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Old 9th Apr 2021, 6:19 pm   #1482
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Default Re: Non-working Commodore PET 3016

Quote:
Originally Posted by SiriusHardware View Post
Blimey!!!

So fingers crossed, put everything back as it should be and... see what happens now.

Note to Slothie: You forgot to update the version number. . But thanks for that, that made it so much easier to see that problem.
Yeah I noticed that the day after I posted when I was checking something. I didn't think it was worth re-posting just for one character!
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Old 9th Apr 2021, 6:22 pm   #1483
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Default Re: Non-working Commodore PET 3016

I'm not sure I know what to say.

Colin.
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Old 9th Apr 2021, 6:27 pm   #1484
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Default Re: Non-working Commodore PET 3016

Is the dark text on the right side a camera artifact or does it look like that IRL?
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Old 9th Apr 2021, 6:27 pm   #1485
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Default Re: Non-working Commodore PET 3016

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I'm not sure I know what to say.
"Hello World"?

Last edited by SiriusHardware; 9th Apr 2021 at 6:38 pm.
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Old 9th Apr 2021, 6:29 pm   #1486
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Default Re: Non-working Commodore PET 3016

Well now you're an expert you can find other PETs to fix I guess
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Old 9th Apr 2021, 6:31 pm   #1487
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Default Re: Non-working Commodore PET 3016

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is the dark text on the right side a camera artifact?
I would say it clearly is, caused by 'beating' between the camera frame rate and the screen refresh rate.

There might be a few minor niggles still to sort, keyboard needs to be tested, IEEE interface may need sorting out, but this is a very good place to be in.
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Old 9th Apr 2021, 6:33 pm   #1488
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Default Re: Non-working Commodore PET 3016

Just all round...
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Old 9th Apr 2021, 6:38 pm   #1489
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Default Re: Non-working Commodore PET 3016

That's just the refresh rate working its way across my phone camera's screen - it doesn't look like that to the naked eye.

Colin.


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Is the dark text on the right side a camera artifact or does it look like that IRL?
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Old 9th Apr 2021, 6:38 pm   #1490
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Default Re: Non-working Commodore PET 3016

I am almost sad this edge of your seat series is reaching its climax... Well done all around.
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Old 9th Apr 2021, 6:39 pm   #1491
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Default Re: Non-working Commodore PET 3016

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Originally Posted by SiriusHardware View Post
Quote:
is the dark text on the right side a camera artifact?
I would say it clearly is, caused by 'beating' between the camera frame rate and the screen refresh rate.

There might be a few minor niggles still to sort, keyboard needs to be tested, IEEE interface may need sorting out, but this is a very good place to be in.
Absolutely, its been quite a struggle, several duff chips and considering Colin's had a pretty steep learning curve its quite an acheivement!
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Old 9th Apr 2021, 6:42 pm   #1492
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Default Re: Non-working Commodore PET 3016

I'm going to have a couple of pints. And then I'll thank you all properly.

It repeatedly boots just fine.

The keyboard needs attention - not many of the keys work but some do. There seem to be plenty of web pages giving advice on how to disassemble, clean and reassemble the keyboard so I don't intend to trouble anyone here with that unless I can't get anywhere.

I have three datasettes to mess with and I have already bought a replacement set of belts so I will start with them. Are there simple scope tests I can do on the tape drive ports?

Sirius - do you think we should have a grand closedown of this thread and for me to open a new one if I find other faults, or is the IEEE worth testing first in this thread?

Colin.
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Old 9th Apr 2021, 6:45 pm   #1493
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Default Re: Non-working Commodore PET 3016

I think it isn't over until it is over, so let's just carry on to wherever this ultimately ends up. Just keep us updated with how you are progressing, it will be nice to see it running something eventually.
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Old 9th Apr 2021, 6:51 pm   #1494
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Default Re: Non-working Commodore PET 3016

Congratulations, so glad you had the patience and determination not to replace all the ram chips.

I think the IEEE, keyboard and datasette refurbs would be good to have separate threads, so its easier for anyone else to find later, but I think you should keep this thread open until the PET is in complete working order again and post final pictures of it doing something.
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Old 9th Apr 2021, 6:53 pm   #1495
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Default Re: Non-working Commodore PET 3016

Oh, by the way, Daver2's test code will probably work as intended now if you fit that in UD8 position. I think it has a low level keyboard test, among other things.
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Old 9th Apr 2021, 7:02 pm   #1496
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Default Re: Non-working Commodore PET 3016

Well when I'd said that changing just UE10 for now would hopefully make a 'significant difference', I wasn't quite expecting it to quite get that far!
- So a very welcome result, and congratulations (You even got a Selfie with it in the first screen's reflection!)

And most surprising, that with so many TTL IC failures, that the usually more fragile RAM IC's have all survived!
- Hopefully those intermittent screen errors you'd had will also have gone away.


Plus, presumably that daver2 PETTESTER EPROM will now get past the screen test and do it's test on the main RAM. So it might be worth trying that one as well, whilst it's working - just to check that it does run OK, in case it might be useful in future.

There's been a few recent datasette on PET's fixed, so should hopefully be able to get those you have working - although I'd expect at least one works electrically, at least.
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Old 9th Apr 2021, 7:20 pm   #1497
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Default Re: Non-working Commodore PET 3016

Just want to add my congratulations! I've been following this thread, and always looking for the next instalment! I kept out of the way as I know absolutely nothing about these things, well done for persevering with it, I'd have probably given up about 60 pages back!

Regards,
Lloyd
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Old 9th Apr 2021, 8:16 pm   #1498
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Default Re: Non-working Commodore PET 3016

On the survival of the RAM chips I suspect the buffers did their job and protected them it is likely that timing errors caused several buffers to drive at the same time wiping each other out... Just a theory...
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Old 9th Apr 2021, 8:32 pm   #1499
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Default Re: Non-working Commodore PET 3016

Wow! That's fantastic!
Code:
10PRINT"IT WORKS!"
20GOTO10
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Old 9th Apr 2021, 11:08 pm   #1500
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Default Re: Non-working Commodore PET 3016

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Originally Posted by Timbucus View Post
On the survival of the RAM chips I suspect the buffers did their job and protected them it is likely that timing errors caused several buffers to drive at the same time wiping each other out... Just a theory...
Colin also changed some of the chips controlling the buffers, so its possible they went first and left the buffers fighting against each other. It might have been a lucky break that the control logic for CAS and RAS also failed which kept the ram outputs out of the fight.
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