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Old 14th Apr 2021, 7:19 am   #1621
SiriusHardware
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Default Re: Non-working Commodore PET 3016

I did find some potential replacement contact dimples, but it depends whether the original ones can be removed and are the same size. (#1603).

To answer Owen's question, yes, the 74LS145 was replaced and did have the hoped for effect, but there is also a secondary problem where some of the carbon contacts on the plungers are dead as well. Colin has tested every key position by using a known good key plunger to activate each one.
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Old 14th Apr 2021, 9:41 am   #1622
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Default Re: Non-working Commodore PET 3016

Quote:
Originally Posted by ScottishColin View Post
I will have to buy some paint yet to restore the case - if anyone happens to know a good match for Commodore PET cases, that would be good.
Quote:
Originally Posted by SiriusHardware View Post
Regarding restoration of the casings, I think AJ (ajgriff) might be the man to speak to about that.
Automotive paint suppliers will match the (aged) paint and provide rattle cans at a price. However, an exact match isn't so critical if the whole case is to be resprayed, as in this assistance. I used white radiator enamel to spray paint the top and sides of my PET's monitor.

As always preparation is the key to a successful repaint and I'd strongly recommend stripping the case completely before rubbing down and neutralising the rusty areas. Fill any pitting with knifing putty folowing the instructions on the tube. It'll be a long job if Colin is looking for a really satisfactory finish.

Alan
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Old 14th Apr 2021, 1:06 pm   #1623
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Default Re: Non-working Commodore PET 3016

It's a bit of a mess so needs doing. I plan to do the whole case and the black base too.

I'm not really up for the expense of getting matched paint at an automotive supplier. Did you just use white? Mine looks off-white rather than plain white.

Colin.


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Originally Posted by ajgriff View Post
Quote:
Originally Posted by ScottishColin View Post
I will have to buy some paint yet to restore the case - if anyone happens to know a good match for Commodore PET cases, that would be good.
Quote:
Originally Posted by SiriusHardware View Post
Regarding restoration of the casings, I think AJ (ajgriff) might be the man to speak to about that.
Automotive paint suppliers will match the (aged) paint and provide rattle cans at a price. However, an exact match isn't so critical if the whole case is to be resprayed, as in this assistance. I used white radiator enamel to spray paint the top and sides of my PET's monitor.

As always preparation is the key to a successful repaint and I'd strongly recommend stripping the case completely before rubbing down and neutralising the rusty areas. Fill any pitting with knifing putty folowing the instructions on the tube. It'll be a long job if Colin is looking for a really satisfactory finish.

Alan
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Old 14th Apr 2021, 1:10 pm   #1624
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Default Re: Non-working Commodore PET 3016

Here's a link to a photo of the PET's version.

https://drive.google.com/file/d/1cO2...ew?usp=sharing

They're c. 9.30mm dia and 5.70mm high.

The actual contact is 4mm dia and c. 1mm high (not easy to measure).

Colin.


Quote:
Originally Posted by SiriusHardware View Post
I did find some potential replacement contact dimples, but it depends whether the original ones can be removed and are the same size. (#1603).

To answer Owen's question, yes, the 74LS145 was replaced and did have the hoped for effect, but there is also a secondary problem where some of the carbon contacts on the plungers are dead as well. Colin has tested every key position by using a known good key plunger to activate each one.
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Old 14th Apr 2021, 1:16 pm   #1625
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Default Re: Non-working Commodore PET 3016

Many of the 3016 series had plastic cases rather than the steel ones of the 2001 series, so you many need to get paint suitable for plastic surfaces. Fortunately car spares places like Halfords** have "bumper paint" in a huge array of colours. Choose an off-white colour rather than diamond white.If you're going to respray it all then an exact match is not vital.

**other automotive paint suppliers are available
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Old 14th Apr 2021, 1:16 pm   #1626
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Default Re: Non-working Commodore PET 3016

Yep - the new IC fixed the keyboard woes. I then found a broken track but managed to solder a wire across the gap and covered it with clear nail varnish to secure it. All the keypads now work, but not all the keys themselves, I'll give them another clean with IPA - I had the whole keyboard apart and washed/cleaned every single component. The keyboard was (not surprisingly due to its age) a mess, but it's clean up nicely.

I followed this video - was very useful to me.

https://www.youtube.com/watch?v=xkoVVbdky_o

I've not added in labour costs - mine or all yours....I think it's for the best.

As someone else said, without numbers, I can't type a program in. This Keyboard Fix is on the way.

https://www.amazon.co.uk/gp/product/...?ie=UTF8&psc=1

Colin.

Quote:
Originally Posted by ortek_service View Post
So I presume you must have received the new 74LS145 today, and swapping this did actually fix the odd fault you had after all?
- It had seemed it couldn't really be anything else, but good to have this confirmed and hadn't had to pay for anything unnecessary

It's probably not been a bad investment money wise (If you exclude your labour costs like they also seemed to on earlier Wheeler Dealers!), especially from noticing some recent asking prices for PET's (especially in the USA) - even higher than >15 years ago.
Although still much cheaper than the various IBM's originally cost in the 80's, until Compaq etc. started off all the compatibles after IBM lost the battle over alternative BIOS's, the hardware architecture was quite open, Plus DOS was sold separately by Microsoft.
I do recall using IBM's OS/2 on our lab's local server for a while but it seemed MS Windows Server replaced that for many after Windows had caught on.

I presume you have tried cleaning again the conductive-rubber plungers, but they still don't work reliably enough.
And had wondered if the conductive rubber can be extracted from the plastic and turned upside-down if it is conductive throughout and not just one face, but is seems the outer non-conductive rubber is also the 'spring' on these. I had seen a PET keyboard completely stripped-down, to clean everything, where they said that was the only way to ensure it was reliable: https://www.commodorecomputerclub.co...4032-keyboard/

Rather than suggested fixes, here: https://www.vintagecomputer.net/brow...ead.cfm?id=703 (or the 'silver paint' mixture in that video, which I think was from a Chemtronics? repair kit design for keypads?)
I suppose you could always fit the worst plungers on the less used keys - like the numeric keypad - for now.
So be able to type the Hello World etc. programs easier...
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Old 14th Apr 2021, 1:27 pm   #1627
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Default Re: Non-working Commodore PET 3016

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Originally Posted by Slothie View Post
Many of the 3016 series had plastic cases rather than the steel ones of the 2001 series, so you many need to get paint suitable for plastic surfaces.
Colin's case is definitely steel as indicated by the rust blotches in some of his photos.

Alan
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Old 14th Apr 2021, 2:12 pm   #1628
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Default Re: Non-working Commodore PET 3016

Very much steel -the serial number label on the back actually identifies it as a 2001-16N BS.

Colin.


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Quote:
Originally Posted by Slothie View Post
Many of the 3016 series had plastic cases rather than the steel ones of the 2001 series, so you many need to get paint suitable for plastic surfaces.
Colin's case is definitely steel as indicated by the rust blotches in some of his photos.

Alan
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Old 14th Apr 2021, 3:22 pm   #1629
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Default Re: Non-working Commodore PET 3016

Quote:
Originally Posted by ScottishColin View Post
I'm not really up for the expense of getting matched paint at an automotive supplier. Did you just use white? Mine looks off-white rather than plain white.

Colin
I'm not sure whether or not the original finish was off-white as most white paints tend to yellow slightly with age. In any case I used pure white radiator enamel partly because I happened to have a couple of cans in stock. Also radiator enamel provides a tough finish and is formulated to resist long term yellowing.

One thing that's difficult to replicate by spraying is the original slightly textured finish. Worth noting that the steel cases were made by Commodore's filing cabinet/office furniture manufacturing subsidiary so goodness knows what painting/coating process was used.

My monitor now has a glossy pure white finish but I don't think many casual observers would notice the slight shade/texture contrast between it and the base unit. With your PET the whole thing will be consistent (and smart!) anyway.

Alan
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Old 14th Apr 2021, 3:27 pm   #1630
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Default Re: Non-working Commodore PET 3016

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Originally Posted by julie_m View Post
The numeric pad provides the only way to type numbers on a PET.
Thanks - It's been a while since I used one / looked at my Chicklet one, and looks like the PET is very unusual in not having the numbers on the keypad, needing to actually use the keypad, with not just using shift on the numbers to get the (non-graphics) symbols on the keys.

However, I've just seen on the latest Keyboard repair video posted here, that they show a PET 2001(N?) with a full-size Keyboard+Keypad that does also have the numbers on the top row of the Keyboard!
So it seems there are even more variations on these keyboards (not just matrix wiring) and I presume there must be country-specific Edit? ROM's that deal with how the top row of the particular keyboard is handled.


Quote:
Originally Posted by ScottishColin View Post
Yep - the new IC fixed the keyboard woes. I then found a broken track but managed to solder a wire across the gap and covered it with clear nail varnish to secure it. All the keypads now work, but not all the keys themselves, I'll give them another clean with IPA - I had the whole keyboard apart and washed/cleaned every single component. The keyboard was (not surprisingly due to its age) a mess, but it's clean up nicely.

I followed this video - was very useful to me https://www.youtube.com/watch?v=xkoVVbdky_o

As someone else said, without numbers, I can't type a program in. This Keyboard Fix is on the way https://www.amazon.co.uk/gp/product/...?ie=UTF8&psc=1
Thanks for the info - Good to hear this did cure it (well the main fault at least).
It will be interesting to see how well that Keypad repair kit works - I've probably got some remote controls that might benefit from a dose, as keys aren't as good as new even after cleaning, so may be tempted to get one.
From their picture, It does look like you get rather a lot in that small tub! (Another listing said you got 10ml - enough for 400 contacts)
But there wasn't much in 2-part mix in the first repair video (where they'd put magnet on the PET case to show which was actually metal) I'd seen
- which isn't surprising when conductive silver paint has always been expensive for tiny vials of it. Although maybe that Keypad repair stuff is more like carbon / flexible, if rated for 2m presses?

Regarding PET case colour, I suppose virtually all original ones may have now gone a bit yellow with age / sunlight exposure. So maybe Radiator - White Matt? is a bit bright - but maybe not as bad as the hand painted gloss on some of these compared to the original possibly anodised / enamelled or powder coating (the best way of getting that Leatherette finish - Although I seem to recall you can get 'Crackle' (Hammerite?) spray paint for restoring the right look to cases.

Last edited by ortek_service; 14th Apr 2021 at 3:34 pm.
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Old 14th Apr 2021, 3:49 pm   #1631
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Default Re: Non-working Commodore PET 3016

Quote:
Originally Posted by ortek_service View Post
Regarding PET case colour, I suppose virtually all original ones may have now gone a bit yellow with age / sunlight exposure. So maybe Radiator - White Matt? is a bit bright - but maybe not as bad as the hand painted gloss on some of these compared to the original possibly anodised / enamelled or powder coating (the best way of getting that Leatherette finish - Although I seem to recall you can get 'Crackle' (Hammerite?) spray paint for restoring the right look to cases.
From my experience of stripping the monitor using ordinary paint stripper I'm pretty sure the original finish was plain old cellulose or acryllic paint. Personally I don't think either a wrinkle or hammered finish would look the part at all. Far better to go for gloss white in whatever shade Colin thinks appropriate.

Alan
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Old 14th Apr 2021, 4:07 pm   #1632
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Default Re: Non-working Commodore PET 3016

I thought they might have used a fine-pitch ripple on the upper white part of these, as it can make it a bit tougher / scratch-resistant and less prone to showing finger prints than a smooth coating. Although the black base was the more common anodised / enamel?

The bit later BBC Computer (plastic) cases and matching metal disk-drive plinths used to use the rippled approach, that seemed to work quite well (although still went yellow, especially the earlier ones with coarser ripple finish)
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Old 14th Apr 2021, 4:20 pm   #1633
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Default Re: Non-working Commodore PET 3016

I wonder what it would cost for a body shop to spray it? It's a bit smaller than one of those things we dare not speak of here, so who knows, could be quite reasonable. The main thing is you'd have to remove or mask any decals / labels.

I've used the black / rubbery conductive paint to repair a few of my remote control buttons, such as power on / off and volume up / down after they went dead. They are still working but for any currently dead keys which are liable to take a hammering (such as 'A', 'fire' on Space Invaders?) I would move a 'fresh' original contact from a little used key to that position and put the re-coated key in the lesser used position.

Don't be afraid to roughen the surface of the old conductive blobs prior to application of the new 'skin' of conductive rubber - if the original surface is too smooth and shiny - often the case on a worn contact - then the new layer will just slide off it like a little black pancake.
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Old 14th Apr 2021, 4:25 pm   #1634
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Default Re: Non-working Commodore PET 3016

From my memory the paint on my 2001 was a sort of silk white with little lumps in it (similar to the old "eggshell" paint). It wasn't particularly "gloss", more like that textured finish you get on plastic casings but less well defined.
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Old 14th Apr 2021, 4:33 pm   #1635
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Default Re: Non-working Commodore PET 3016

For the contact problem there are also the likes of these

https://www.amazon.co.uk/1-5mm-10mm%.../dp/B084R8GGVX

But then you still have a different problem, how to slice off the original blob leaving a nice clean, flat surface for the new one to attach to: And how do you then make it stay attached?
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Old 14th Apr 2021, 5:10 pm   #1636
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Default Re: Non-working Commodore PET 3016

OK - so here's a thing that may be useful to others.

While I'm waiting for the conductive paint to turn up, I tried something I've seen recommended elsewhere. I took a normal A4 blank sheet of paper and folded it up. Carefully, I rubbed it on each of the conductive pads on the bottom of the keys. It actually got quite dirty. I plugged/screwed the keyboard back together and all the keys bar 4 worked just fine.

I gave those 4 a working over with the paper and I now have a fully working keyboard. So I guess I've gone too early on the conductive paint, but if my paper-rubbing fix turns out to be temporary, it'll be useful.

Anyway - the keyboard is screwed back in and fully working.

What remains now is to test the ports - I can test the second cassette port easily enough.

Can anyone help with code to test the remaining ports?

Colin.
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Old 14th Apr 2021, 5:42 pm   #1637
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Default Re: Non-working Commodore PET 3016

The original "Basic 1" commodore PET (With the "*** Commodore Basic ***" banner rather than the "### Commodore Basic ###") had built in diagnostics that would activate by holding down a pin on the user port. Later versions aparrently removed this feature rendering the LED on the main board redundant (possibly not fitted?). Commodore also made a cable loom that connected to the keyboard, cassette ports, user port & IEEE port and tested the ports - I beleive the software came on cassette. I looked for a link to information on this, but ten or so minutes of searching yeilded nothing (sadly theres so much C64 information it tends to get lost) but I did find the attached manual which might be interesting or give some clues/useful info. Looking through the archive sites on zimmer.net or 6502.org might prove fruitful. Other than that testing the user port would mostly be a matter of POKEing to the port and measuring the levels on the pins, or connecting to CB2 to see if you can get tones etc. A good reference for this is "The PET Revealed" by Nick Hampshire, copies easily found online. The IEEE port being bidirectional would be more of a hassle without some kind of test fixture unless you can get a IEEE peripheral and cable and check it out that way!
Attached Files
File Type: zip Testing_The_PET_Computer.pdf.zip (1.73 MB, 10 views)
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Old 14th Apr 2021, 5:45 pm   #1638
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Default Re: Non-working Commodore PET 3016

Well, now that you are able to issue BASIC commands you can try these for a first-line check of the IEEE 488 port. This port is probably only important if you plan to acquire a disc drive or something which pretends it is one, such as the SD2PET.

Notice the POKE address is slightly different to the PEEK address in both cases.

Code:
POKE 59426,0
PRINT PEEK(59424)
Result=?

Code:
POKE 59426,255
PRINT PEEK(59424)
Result =?

The IEEE port has an unusually useful structure in so far as the state of the output latches can be read by the input buffers, so you can write a value to the 8 data bits of the IEEE port and read that value back, in the process proving both the output latches and the input buffers - provided the value you read back in is the same as the value you wrote out.
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Old 14th Apr 2021, 6:13 pm   #1639
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Default Re: Non-working Commodore PET 3016

No LED and ### instead of *** here.

I tried to look for that information before and couldn't find any trace of the hardware or software.

Colin.


Quote:
Originally Posted by Slothie View Post
The original "Basic 1" commodore PET (With the "*** Commodore Basic ***" banner rather than the "### Commodore Basic ###") had built in diagnostics that would activate by holding down a pin on the user port. Later versions aparrently removed this feature rendering the LED on the main board redundant (possibly not fitted?). Commodore also made a cable loom that connected to the keyboard, cassette ports, user port & IEEE port and tested the ports - I beleive the software came on cassette. I looked for a link to information on this, but ten or so minutes of searching yeilded nothing (sadly theres so much C64 information it tends to get lost) but I did find the attached manual which might be interesting or give some clues/useful info. Looking through the archive sites on zimmer.net or 6502.org might prove fruitful. Other than that testing the user port would mostly be a matter of POKEing to the port and measuring the levels on the pins, or connecting to CB2 to see if you can get tones etc. A good reference for this is "The PET Revealed" by Nick Hampshire, copies easily found online. The IEEE port being bidirectional would be more of a hassle without some kind of test fixture unless you can get a IEEE peripheral and cable and check it out that way!
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Old 14th Apr 2021, 6:13 pm   #1640
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Default Re: Non-working Commodore PET 3016

First result 0

Second result 126.

Does that match what is supposed to happen?

Colin.


Quote:
Originally Posted by SiriusHardware View Post
Well, now that you are able to issue BASIC commands you can try these for a first-line check of the IEEE 488 port. This port is probably only important if you plan to acquire a disc drive or something which pretends it is one, such as the SD2PET.

Notice the POKE address is slightly different to the PEEK address in both cases.

Code:
POKE 59426,0
PRINT PEEK(59424)
Result=?

Code:
POKE 59426,255
PRINT PEEK(59424)
Result =?

The IEEE port has an unusually useful structure in so far as the state of the output latches can be read by the input buffers, so you can write a value to the 8 data bits of the IEEE port and read that value back, in the process proving both the output latches and the input buffers - provided the value you read back in is the same as the value you wrote out.
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