• Please review our updated Terms and Rules here

Commodore Pet Chiclet 2001-8 bs Repair

Pet Rescue

Experienced Member
Joined
Dec 15, 2010
Messages
484
Location
Staffordshire, England
Hi all, well at last I bagged myself a 2001 chiclet model its a 2001-8 bs.

You guessed it it's a non working unit.

Upon turning on you get the dreaded garbage screen.

The board type is 320351 assy the newer one with the holes punched out and 4108 ceramic ram chips.

I first tested all the voltages +9v unregulated the -5v +5v +12v etc then reseated all of the chips but no joy.

I have a 4008 with the exact same board minus the punched holes. I in turn swapped the big chips one by one.
The 6502 was fine, as was the 6522, one 6520 was fine but the other one was faulty. Next I swapped the roms one
by one.

UD9 901465-03 Fine
UD8 901447-24 Fine
UD7 901465-02 Fine
UD6 901465-01 Fine
UD10 901447-10 Fine

I then used the MikeS's advice off this forum to use an NOP adaptor. (advice given on a previous 3032 repair)

I popped in the adaptor and went through all the address lines and they checked out fine.
The clock signals in and out were fine, the reset circuit worked fine low for a second then high.
RDY/NMI/IRQ all high. But noticed the sync was low.

Also noticed that the board had some previous work on UC3 and UE5. but they both looked fine.

Next I bit the bullet and swapped the 2114 static video rams after piggybacking did nothing.
The garbage altered but still no joy damn I hoped it was them.

Next I socketed all of the 4108 rams again after piggybacking with no joy.
Put in 8 X 4116's but still no joy.(they work the same as 4108's I believe.)

Right time to go over the simple things, I started with the 6502 to make sure the pins continuity
went through to the board. Well well well pin 33 had no continuity!! I pushed the leg of a resistor in to
clean up any corrosion in the hole and popped the 6502 back in and the continuity was back.

Turned on the computer and Yes!! Get in "Commodore basic 7167 bytes free!!"

I then to satisfy my curiosity, put back the two original 2114's and it still worked!!

So next I put back the ceramic 4108's back and get in!! they still worked, I really love using my heat gun to
replace chips as it hardly ever damages them.

So the moral of this story is get a heat gun they are ace and if you get a garbage screen you are really
best to check continuity on the sockets Big chips and ROM's.

As you may of read a previous post where I failed to repair a 3032 pet and it has always bugged me what
was wrong and that I didn't fix it.

I feel I've exorcised that demon by fixing the same board with the same fault.

Sorry for the Long post but I hope this helps others who have a similar fault.
 
Yeah, that was a good read. I appreciate your posting it. I wonder about using a heat gun to desolder chips though...is that really safe?
 
Congrats on a great job!

Thanks dave_m with your help, MikeS's and other members on the 3032 repair it layed down the foundations
of what to look for on this repair. I was very nearly back on here for advice but luckily found the bad
continuity on D0 on the 6502. The NOP was a really useful tool too I was able to see the chip selects etc.

Yeah, that was a good read. I appreciate your posting it. I wonder about using a heat gun to desolder chips though...is that really safe? .

Thanks KevinO I hope it wasn't too long winded but wanted to put it down as it happened. Regarding the
heat gun it is a really good tool. I don't think I've damaged any chips from them getting too hot so far!
It's removed rams and logic as well as CPU and PLA's etc without damage which is great like on the last
project when you are not sure if an item is faulty and enables you to put back a good item if ok.
The only drawback is if you leave it on too long it can bubble the PCB but you start to get a feel for it
after practicing on a scrap board.

Yay! Now I'm not the only person here with a dynamic board 2001-8. .

Eudimorphodon is it unusual then to have a dynamic board in a chicklet pet? it does look like the original
board. The chips are 79-80, to be honest I was glad it was the dynamic board as I have more experience
on them than older boards and you can get the chips easier having no 6550 rams etc.

P.S. What is your serial number? I found your other post on the 2001-8 having a dynamic board. Oh nearly forgot have you got the dates on your chips? Could be from a last batch of chiclets! Also my name badge does not say
PET but CBM in large letters, 2001 underneath and profesional computer to the side like the 3000/4000's
 
Last edited:
Eudimorphodon is it unusual then to have a dynamic board in a chicklet pet? it does look like the original board. The chips are 79-80, to be honest I was glad it was the dynamic board as I have more experience
on them than older boards and you can get the chips easier having no 6550 rams etc.

P.S. What is your serial number? I found your other post on the 2001-8 having a dynamic board. Oh nearly forgot have you got the dates on your chips? Could be from a last batch of chiclets! Also my name badge does not say PET but CBM in large letters, 2001 underneath and profesional computer to the side like the 3000/4000's

So... prior to yours I haven't heard of any other "Dynamic 2001s" out there in the wild. Next time I get a chance to crack the thing open and play I'll look at the IC data stamps; the only one I'm pretty sure of is I think the the Z-80 has a manufacturing date of 1980, which... I'm not sure how badly affects the case for it being the original board. I haven't had any luck finding a firm date at which Commodore discontinued the Chicklet models; one FAQ-ish thing I found implied that there was at least a few months overlap between the "2001-N" models and the Chicklets being "discontinued", and Commodore being Commodore they probably kept making Chicklets until the parts bins for them ran dry. (Likely sending them to fulfil orders from schools and such.)

The counter-argument for it being the original board is the machine also has a "REMANUFACTURED" sticker on the back.

I'll also check out the S/N; the badge on my system says "PET" but it also says "Professional Computer" off to the side. (My 9" 4032, by contrast, just says "Computer".) You'd swear whoever was turning out the case stickers was just slapping whatever tickled their fancy that day on any given production run.
 
Thanks dave_m with your help, MikeS's and other members on the 3032 repair it layed down the foundations
of what to look for on this repair. I was very nearly back on here for advice but luckily found the bad
continuity on D0 on the 6502. The NOP was a really useful tool too I was able to see the chip selects etc.



Thanks KevinO I hope it wasn't too long winded but wanted to put it down as it happened. Regarding the
heat gun it is a really good tool. I don't think I've damaged any chips from them getting too hot so far!
It's removed rams and logic as well as CPU and PLA's etc without damage which is great like on the last
project when you are not sure if an item is faulty and enables you to put back a good item if ok.
The only drawback is if you leave it on too long it can bubble the PCB but you start to get a feel for it
after practicing on a scrap board.



Eudimorphodon is it unusual then to have a dynamic board in a chicklet pet? it does look like the original
board. The chips are 79-80, to be honest I was glad it was the dynamic board as I have more experience
on them than older boards and you can get the chips easier having no 6550 rams etc.

P.S. What is your serial number? I found your other post on the 2001-8 having a dynamic board. Oh nearly forgot have you got the dates on your chips? Could be from a last batch of chiclets! Also my name badge does not say
PET but CBM in large letters, 2001 underneath and profesional computer to the side like the 3000/4000's

This is getting as weird for me, I have the same CBM 2001 you mentioned but it had no chiclet? It has a normal keyboard like the rest of the pets. Weird.
 
Wow! I thought that dynamic boards in a chiclet case were rare, but a 2001-8 with a Z-80? ;-)

Doh! Yeah, that was silly of me. :)

I think my only defense is yesterday I was talking to someone about their quest to find a working z-80 SoftCard for their Apple IIe. Must have given myself a bad case of Zilog-itis...
 
The counter-argument for it being the original board is the machine also has a "REMANUFACTURED" sticker on the back.

Am I right in saying yours has remanufactured on the back?

Just to clarify there are no such stickers on mine, but have to say it's in remarkably good condition.
It has a red rubber thing over the brightness control on the monitor, I don't know if that's original too.

My 4008 also only has "computer" on the side and "not personal computer" but hasn't got the second bank
of ram punched out? Like the chicklet has.

This is getting as weird for me, I have the same CBM 2001 you mentioned but it had no chiclet? It has a normal keyboard like the rest of the pets. Weird.

Commodore's labels are very confusing I must admit too! I don't know what the bs stands for in 2001-8 bs!
 
Hmm... the -B usually meant a Business keyboard (11-key keypad vs. 20 keys on the -N version) but I don't know about the -S; a country code perhaps? I think there was a Sweden-specific model, for example.
 
Swedish PETs were factory modified by the importer Datatronic. As far as I know, none of them have a custom model number on the back side. Also I can't recall ever seeing or hearing about a chicklet PET with Swedish characters, only the latter models with full travel keyboard. The only custom chicklet model I know is the Japanese PET 2001.
 
When looking on the internet some other 2001-8 bs models are shown with full size keyboards too!
so it can't be to do with the keyboard style! I wonder if it's to mark with the change over from chicklet to
full size keyboards or models with dynamic boards? Are the non dynamic board 2001-8 pets b's or bs's also.
 
Pet Rescue,
Do I understand correctly that you have a chicklet keyboard with the business character set? Does depressing a key gives a lower case letter and a shifted key gives an upper case letter rather than a graphic character? I assume there are graphic characters on the keyboard as usual?
-Dave
 
Pet Rescue,
Do I understand correctly that you have a chicklet keyboard with the business character set? Does depressing a key gives a lower case letter and a shifted key gives an upper case letter rather than a graphic character? I assume there are graphic characters on the keyboard as usual?
-Dave

Hi Dave I am not sure I'll have to try it tomorrow one thing I did notice was when I loaded a game the writing on the
game was the wrong way around, where the capital should be it was lower case and where the lower case should be it
was upper if you know what I mean oh and yes there are graphic characters on the keyboard as usual.

When typing load I pressed shift + " and a graphic symbol came up, force of habit when pressing shift + 2
 
Hi Dave I have just checked, if you press a key you get upper case letters. Then if you press shift you get graphic symbols. If you type the poke 59468,14 for lower case you get lower case normal and upper case with shift.
 
Last edited:
OK, then you have the normal graphics keyboard and editor ROM that are in all chicklet PETs. So the 'B' in your ID plate does not stand for 'business'.
 
OK, then you have the normal graphics keyboard and editor ROM that are in all chicklet PETs. So the 'B' in your ID plate does not stand for 'business'.
No, I don't think there was ever a Business version with a chiclet keyboard, but there was a lot of swapping going on; when I bought my 2001 brand new I replaced the chiclet keyboard on mine with a 'normal' graphic keyboard and upper case half as soon as they became available and it's not inconceivable that someone did the reverse. Unfortunately the serial number is on the bottom part of the case which is of course the same.

Regarding the character set, note that the early BASIC 1 PETs had reversed case, i.e. normally caps and shift for lower case.

The 'B' did stand for 'CBM Business', at least on later models, but I think it's pretty clear by now that Commmodore played pretty fast & loose with their various models and model numbers (which may be what the 'BS' refers to ;-) ).

An interesting reference:
http://zimmers.net/cbmpics/cbm/PETx/petfaq.html
 
Regarding the reverse swap I will have to check the monitor crt and video board to see if the date stamp matches
the mainboard chips which are 79/80 so I can rule out whether the top half has been swapped back to a chicklet.
Will the top case have a date stamp on it anywhere, I have noticed some round ink stamps but not sure what they
are. (maybe quality control ones)
 
Back
Top