PET is working but.......

[CBdicX]

Hello, i have a first model PET (i am also looking for the sticker(s) and when i turn on the power it comes with a lot of numbers on the screen..not the text that i see in the manual: Commodore Basic ect.ect.
What is wrong, and if someting is wrong what can i do to fix it.
regards,
CBdicX - Almere - Holland

[Personable85]

I can't be certain, but it sounds like you have ROM damage. The only thing you can do is replace the ROM chips. I'm no expert and other causes might be at fault, but I'd put my money on the ROM.

[CBdicX]

I can't be certain, but it sounds like you have ROM damage. The only thing you can do is replace the ROM chips. I'm no expert and other causes might be at fault, but I'd put my money on the ROM.

Hello, thank you for your reply.

But exact what are the ROM chips you mean as the bord is filled with that stuff (think now they can put them on a fingernail sized chip) and where could i buy replacements ?

[Personable85]

You have what is called a 2001 "chicklet" PET. It is called a chicklet PET because of the chicklet style keyboard. I have a 2001-N series PET. My PET is the next generation of PETs after yours. My PET has the full keyboard and no built-in cassette player. The motherboards in our PETS are similar, but not exactly the same. I'm using my board as reference.

Most of the chips and curcuits on the motherboard are unremoveable. They are soldered into place and can't be easily removed. About the middle of the board you will find a line of white sockets. Some of these sockets will have chips in them and some are empty to accomodate expansion. The chips in these white sockets are your ROM. They should have one or more of the following numbers printed on them depending on your version of ROM:

ROM 1.0 6540 or 901447
ROM 2.0 6540 or 901447
ROM 3.0 6540 or 901465 & 901447

One or all of these chips is probably bad and that's what is probably causing your problem.

Where can you buy replacement ROM? You can't. The 2001 chicklet PET is over 30 years old and Commodore went out-of-business in 1994. There simply are no stores that sell replacement parts. People like myself with PETs get parts by buying broken PETs and using them for parts. That is your best bet.
You can also try searching the Internet for PET parts. Especially try PET and Commodore clubs. The PET was a lot more popular and numerous in Europe than here in America, so your chances are better. But, the chances of finding PET parts are poor at best. Believe me, I've tried.
The best place to buy a 2001 chicklet PET, working or not working, is Ebay. But, be warned! The chicklet PET is very popular on Ebay and you can easily expect to pay $300 or more for one. There are a couple on Ebay(US) right not. I suggest you check them out. Ebay, I believe, is your best hope.
You may find it easier just to sell your PET on Ebay than try to repair it. For those of use who are die-hard PET owners, we never give up the fight to keep out PETs running.
I hope some of this information has helped.

Mark

[CBdicX]

You have what is called a 2001 "chicklet" PET. It is called a chicklet PET because of the chicklet style keyboard. I have a 2001-N series PET. My PET is the next generation of PETs after yours. My PET has the full keyboard and no built-in cassette player. The motherboards in our PETS are similar, but not exactly the same. I'm using my board as reference.

Most of the chips and curcuits on the motherboard are unremoveable. They are soldered into place and can't be easily removed. About the middle of the board you will find a line of white sockets. Some of these sockets will have chips in them and some are empty to accomodate expansion. The chips in these white sockets are your ROM. They should have one or more of the following numbers printed on them depending on your version of ROM:

ROM 1.0 6540 or 901447
ROM 2.0 6540 or 901447
ROM 3.0 6540 or 901465 & 901447

One or all of these chips is probably bad and that's what is probably causing your problem.

Where can you buy replacement ROM? You can't. The 2001 chicklet PET is over 30 years old and Commodore went out-of-business in 1994. There simply are no stores that sell replacement parts. People like myself with PETs get parts by buying broken PETs and using them for parts. That is your best bet.
You can also try searching the Internet for PET parts. Especially try PET and Commodore clubs. The PET was a lot more popular and numerous in Europe than here in America, so your chances are better. But, the chances of finding PET parts are poor at best. Believe me, I've tried.
The best place to buy a 2001 chicklet PET, working or not working, is Ebay. But, be warned! The chicklet PET is very popular on Ebay and you can easily expect to pay $300 or more for one. There are a couple on Ebay(US) right not. I suggest you check them out. Ebay, I believe, is your best hope.
You may find it easier just to sell your PET on Ebay than try to repair it. For those of use who are die-hard PET owners, we never give up the fight to keep out PETs running.
I hope some of this information has helped.

Mark

Hi Mark, thank you for your help.
Would it be possible to swop the motherboard from the later version to this first model ?
It happens that i will receive a later model, but with a transformator that is dead.

Regards, Dick

[rbernardo]

Hello, i have a first model PET (i am also looking for the sticker(s) and when i turn on the power it comes with a lot of numbers on the screen..not the text that i see in the manual: Commodore Basic ect.ect.
What is wrong, and if someting is wrong what can i do to fix it.

Sorry to hear of your problem. I am fortunate to know Ray Carlsen, C= repairperson, who has worked on repairing my PET 4032 and PET 8032.

Truly,

[Personable85]

Hello,
Based on my very limited knowledge of the subject, you cannot put a PET 2001-N series motherboard into a chicklet PET. There are simply too many changes in the two designs. The PET 2001-N series is a complete redesign of the chicklet PET. Although, based on the book I have, Commodore started putting the 901447 ROMs into the later made 8K chicklet PETs. These are the same ROMs (I believe) used in the early 2001-N series PETS. You may not be able to use the PET 2001-N series motherboard in the chicklet PET, but you may be able to remove all the existing ROM in the chicklet PET and replace it with the 901447 ROM from the PET 2001-N series motherboard. That might solve your problem a lot more easily than replacing the motherboards. I have a complete listing of all the ROM chip numbers used in the various PET/CBM computers. Let me know if you want a copy of it.
Thanks!
Mark

[CBdicX]

Hello,
Based on my very limited knowledge of the subject, you cannot put a PET 2001-N series motherboard into a chicklet PET. There are simply too many changes in the two designs. The PET 2001-N series is a complete redesign of the chicklet PET. Although, based on the book I have, Commodore started putting the 901447 ROMs into the later made 8K chicklet PETs. These are the same ROMs (I believe) used in the early 2001-N series PETS. You may not be able to use the PET 2001-N series motherboard in the chicklet PET, but you may be able to remove all the existing ROM in the chicklet PET and replace it with the 901447 ROM from the PET 2001-N series motherboard. That might solve your problem a lot more easily than replacing the motherboards. I have a complete listing of all the ROM chip numbers used in the various PET/CBM computers. Let me know if you want a copy of it.
Thanks!
Mark

Hello Mark, yes please send me the list of the ROM chip numbers so i know what to replace and hope to get a working PET
Thank you very much !!

[Personable85]

This information comes from page 387 of PET Personal Computer Guide by Adam Osborne. A great book for PET owners.

PET 2001 (chicklet) 8K

ROM Part# H1 H2 H3 H4 H5 H6 H7 A2
1.0 6540 -011 -013 -015 -016 -012 -014 -018 -010
2.0 6540 -019 -013 -015 -016 -012 -014 -018 -010
3.0 6540 -020 -022 -024 -025 -021 -023 -026 -010

1.0 901447 -01 -03 -05 -06 -02 -04 -07 -08
2.0 901447 -09 -03 -05 -06 -02 -04 -07 -08
3.0 901465 -01 -02 -03 blank blank blank
901447 -24 -08


PET 2001-N series

ROM Part# D3 D4 D5 D6 D7 D8 D9 F10
3.0 901465 blank blank blank -01 -02 -24 -03
901447 -10
4.0 901465 blank blank -19 -20 -21 -29 -22
901447 -10
4.0+ 901465 blank blank -23 -20 -21 -29 -22
901447 -10

So, if your PET 2001 8K (chicklet) has early ROM 2.0, the chips should have the following numbers printed on them for identification:
6540-019
6540-013
6540-015
6540-016
6540-012
6540-014
6540-018
6540-010

For a total of eight ROM chips.

I hope this information helps!

Mark

[CBdicX]

This information comes from page 387 of PET Personal Computer Guide by Adam Osborne. A great book for PET owners.

PET 2001 (chicklet) 8K

ROM Part# H1 H2 H3 H4 H5 H6 H7 A2
1.0 6540 -011 -013 -015 -016 -012 -014 -018 -010
2.0 6540 -019 -013 -015 -016 -012 -014 -018 -010
3.0 6540 -020 -022 -024 -025 -021 -023 -026 -010

1.0 901447 -01 -03 -05 -06 -02 -04 -07 -08
2.0 901447 -09 -03 -05 -06 -02 -04 -07 -08
3.0 901465 -01 -02 -03 blank blank blank
901447 -24 -08


PET 2001-N series

ROM Part# D3 D4 D5 D6 D7 D8 D9 F10
3.0 901465 blank blank blank -01 -02 -24 -03
901447 -10
4.0 901465 blank blank -19 -20 -21 -29 -22
901447 -10
4.0+ 901465 blank blank -23 -20 -21 -29 -22
901447 -10

So, if your PET 2001 8K (chicklet) has early ROM 2.0, the chips should have the following numbers printed on them for identification:
6540-019
6540-013
6540-015
6540-016
6540-012
6540-014
6540-018
6540-010

For a total of eight ROM chips.

I hope this information helps!

Mark

THANK YOU VERY MUCH !!!!!

[Gambit]

I am fortunate to know Ray Carlsen, C= repairperson

I would also recommend Ray, he repaired a C64 and SX64 of mine before.

[j1mt3hcop13rwr3nch]

Aye. .bin files of the various ROMs can be found in several places in the links section too along with explainations of the various versions.

If you have an EPROM programmer available then you need only to figure out what "modern" 27Cxx eprom equivelent will be required to replace the ROM.

There a bit that's not entirely across the board clear to me yet regarding this (regarding the use of the bus address A-11/CE on each individual socket as I think some are mapped differently) but so far I've had luck by burning the files (at least for the editor ROM) in the "top half" (H$0800) of a 2732. (2716's are hard to find now)

If someone can confirm this is an across the board workable rule and you don't have access to an EPROM burner - lemme know which you need, be happy to burn a set for you.