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PET got seriously ill...

Nice work! I suspect someone here will be able to fix you up with a replacement ROM. Otherwise they do pop up now and again on eBay.

If you're really stuck I can program one for you but (a) you'd need to supply the EPROM and (b) it'd have to be adaptable to my el-cheapo programmer (which doesn't support the old PET chips directly). So you'd have to be really stuck, I think ;-)
 
With all those Commodore fans and experts in Holland, Germany, etc. I'd have thought there'd be all sorts of offers...

It's pretty trivial to make an adapter to use a 2732 instead of a 2532, in case that opens some doors, and a programmer's not that hard to build either, for that matter; you'll need one sooner or later...

Here's a simple reader and programmer:
http://www.larwe.com/zws/products/index.html

If all else fails, PM me and I'll see what I can do from over here in far-off Canada...

Where's Anders? He's closer and he has *everything* ;-)

mike
 
I am here, but previously I didn't know what the fault was.

After doing an EPROM inventory, I came up with the following:

5x 2516
12x 2716
2x 2532
7x 2732
12x 2764
5x 27128
2x 27256

It appears one of my two programmers can read/write 2532 chips, so in worst case I could spend one of the last two for this cause.

Does anyone know what to do with 2516 and 2716 EPROMs by the way? They're 2 kB each and while pin compatible with 2532 and/or 2732, rarely you have much use of these small chips.
 
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carlsson said:
Does anyone know what to do with 2516 and 2716 EPROMs by the way? They're 2 kB each and while pin compatible with 2532 and/or 2732, rarely you have much use of these small chips.
Click to expand...
You mean apart from using them as PET editor or character ROMs? ;-)
 
Hi everyone,

thanks for all your kind offers to help me out with my faulty ROM! However, we had some friends visiting us over easter, one of the being an electric engineer, and he reckoned he might be able to burn me a replacement EPROM. We'll give this a try, and I'll let you know how it worked out.

But of course MikeS is right when he says

MikeS said:
you'll need one sooner or later...
Click to expand...

regarding EPROM programmers! I guess I shall get into this sooner or later. (One of the first things I'd like to change is the C64's startup colors -- light blue on dark blue doesn't exactly cause eye cancer, but they couldn't have come up with a less readable colour combination, could they? ;-) )

Thanks again for all your support (and mind, I have some more vintage problems up my sleeve)!
 
Hi there,

still trying to figure out which kind of modern and easily available EPROM could be used as a replacement for my faulty F000 ROM... In spite of the plethora of documents available about the PET, I find it difficult to find out something useful about the original ROMs (they are 6332/6316s, aren't they?), not to mention possible replacements EPROMs -- I'm even unable to find again the web page I got the ROM's pinout from...

I understand the appropriate replacement would be a 2532 (pin-compatible) or 2732 (would need an adapter)? Well, the closest match I could find in some electronics stores' catalogues was called 27C64. I guess it should be possible to fit one of these into the F000 ROM socket by some amount of wiring (and perhaps an additional 74xx for getting the CS levels right) -- or did I miss something?

As for building an EPROM programmer/reader, I am still searching for something nice... Something that could be connected via the serial port would be great, and Linux support is kinda must. Does anyone know such a device?

Regards --
 
Well, a 2764 will need a few more jumpers, but not too bad; you'll just use half of it. If you look up the specs for a 2532 and a 2764 you should find that except for the end pins one side will correspond exactly, while a few pins on the other side will need to be rerouted; no need for any extra parts other than a couple of sockets and some wire.

What I do is take a 28 pin socket and bend out the pins that will be rerouted; then I take a 24 pin socket and solder thin wirewrap wire to the pins that will need to be rerouted. Poke the 28 pin through a piece of paper to insulate the rerouted pins and plug it into the 24 pin.
Make the necessary connections, plug the programmed 28 pin EPROM in the top and plug the whole thing in.

I'd send you a picture but my cheap camera doesn't take close-ups very well. If you really need them I suppose I could look up the connection detail, but it should be pretty obvious; just tie the unused address pin to ground or Vcc, depending on which half you program (or program both halves the same).

Hope that's not to confusing. Did you have a look at the link I sent to a cheap & simple programmer?
 
If you like a pre-programmed 2532, I'll be able to help. However as noted in the other thread, if Bacon2002 actually ended up with a surplus F000 ROM chip, perhaps the two of you could deal unless he wants to keep it as a spare in case more ROMs in his PET go bad.
 
Yeah, that's what I thought, that the one you'd sent wasn't needed and was going to be passed on to our friend here; what happened to that one?
 
Hi everyone,

the other day, the mentioned friend unexpectedly dropped by and brought me his EPROM burner. Together with this...

MikeS said:
Well, a 2764 will need a few more jumpers, but not too bad; you'll just use half of it. If you look up the specs for a 2532 and a 2764 you should find that except for the
[...]
the unused address pin to ground or Vcc, depending on which half you program (or program both halves the same).
Click to expand...

excellent and detailed explanation I should be able to get going as soon as I find the time to order some 2764 chips.

MikeS said:
Hope that's not to confusing. Did you have a look at the link I sent to a cheap & simple programmer?
Click to expand...

Yes, I did; interesting stuff, which might serve as an introduction to this topic. However, with all these "development discontinued" notes datet from the last millenium, I'm somewhat unsure in how far the presented information is still up-to-date. Do you have any experience with those 'EPROMr's?

carlsson said:
If you like a pre-programmed 2532, I'll be able to help. However as noted in the other thread, if Bacon2002 actually ended up with a surplus F000 ROM chip, perhaps the two of you could deal unless he wants to keep it as a spare in case more ROMs in his PET go bad.
Click to expand...

MikeS said:
Yeah, that's what I thought, that the one you'd sent wasn't needed and was going to be passed on to our friend here; what happened to that one?
Click to expand...

Hey, I missed that one... that would, of course, be great -- on the other hand, I really don't want to predate on other people's valuable spare parts collection. So... Bacon2002, do you read this? If so, what do you rekcon? Do you think you could live without a spare F000 ROM? And where do you actually live -- can I afford the shipping costs...? ;-)

Best regards --
 
Bacon's in the UK.

As for 2764 chips, you should be able to find them almost anywhere vintage. Just make sure those are erased, or otherwise you need an UV lamp or EPROM eraser before programming them. I suppose the easiest way would be to duplicate the 4K of code twice on the chip.
 
Carlsson,

carlsson said:
Bacon's in the UK.
Click to expand...

ah, cool, that's not too far away.

carlsson said:
As for 2764 chips, you should be able to find them almost anywhere vintage. Just make sure those are erased, or otherwise you need an UV lamp or EPROM eraser before programming them. I suppose the easiest way would be to duplicate the 4K of code twice on the chip.
Click to expand...

Yepp, my friend also borrowed me his EPROM erasor and gave me some used EPROMs -- haven't had a closer look yet, though, hence I don't know if they're suitable.

As for the 2764, I wouldn't mind spending a couple of Euros for a new one. I found offers for new 27C64 ICs which, I guess, should be fine since -- to my understanding -- CMOS chips usually go well with TTL levels, don't they?

Regards --
 
Hopefully, Bacon_2002 will send you the actual ROM which would be best for your restoration. If he does not, send me your email and shipping address by private message on this forum, and I will send you a 2532 EPROM programmed with the kernal code. Make sure to let me know which version you want.
-Dave
 
Dave,

dave_m said:
Hopefully, Bacon_2002 will send you the actual ROM which would be best for your restoration. If he does not, send me your email and shipping address by private message on this forum, and I will send you a 2532 EPROM programmed with the kernal code. Make sure to let me know which version you want.
Click to expand...

thanks for your generous offer, which I'll gladly accept in case everything else fails! :) I'll try to contact Bacon_2002 over the next days and beg him for his spare ROM. Perhaps I can persuade him to leave it to me if I promised him a can of original German sauerkraut in return... ;-)

All the best --
 
If you can't find a ROM, I saw this item on ebay today.

Commodore PET ROM Chip Adapter (MPS6540 MOS6540 6540). Replaces any MOS ROM chip in the Commodore PET 2001! Item number: 260391689552 . $30US or near offer.

It's not just the adaptor but the seller will program it with the ROM image you want.

Tez
 
track18 said:
Perhaps I can persuade him to leave it to me if I promised him a can of original German sauerkraut in return... ;-)
Click to expand...
Or maybe threaten to send a can if he doesn't deliver the ROM? ;-)

tezza said:
Commodore PET ROM Chip Adapter (MPS6540 MOS6540 6540). Replaces any MOS ROM chip in the Commodore PET 2001! Item number: 260391689552 . $30US or near offer.
Click to expand...
My word - I bought a whole PET for less than that!
 
Hi everyone,

tezza said:
If you can't find a ROM, I saw this item on ebay today.

Commodore PET ROM Chip Adapter (MPS6540 MOS6540 6540). Replaces any MOS ROM chip in the Commodore PET 2001! Item number: 260391689552 . $30US or near offer.

It's not just the adaptor but the seller will program it with the ROM image you want.

Tez
Click to expand...

well, as Cosam pointed out in

cosam said:
My word - I bought a whole PET for less than that!
Click to expand...

that seems a bit overpriced to me, too. I'm not *that* desperate yet -- and I'm actually quite confident that I will be able to build an EPROM adapter myself (with all the good advice I already got from you guys).

MikeS said:
So, have you looked yet? Maybe you have what you need?
Click to expand...

I got a collection of approx. 20 EPROMs of all shapes and sizes, tow of them being labelled 'NMC27C64Q' -- haven't figured out yet what 'NMC' and 'Q' stand for, but I guess those would be the most promising candidates.

cosam said:
Or maybe threaten to send a can if he doesn't deliver the ROM? ;-)
Click to expand...

Appropriately prepared (with bay leaves, juniper berries, a dash of white wine and diced apples [I'm talking about fruits here ;-)]), it's a delicacy that goes particularly well with bratwurst. :)

Regards --
 
Well, you've got the eraser, you've got reasonably close EPROMS and I assume you've got (use of) a programmer; all you need is a couple of sockets and/or some thin wire and you're in business. What else did ya get; maybe there's something even closer?
 
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