View Full Version : Testing a C64 with normal basic commands

4th February 2012, 17:21
Just wondering, is there a way to test a C64 with normal basic commands ?
Perhaps some pokes or something ?

Thing is I sold a C64 to everblue here and I tested it with a tester cartridge and everything tested ok but he is having troubles now with an easy flash cart and doesn't have any drive's or datassette's so no other way to test it.



4th February 2012, 17:48
What kind of problems?

4th February 2012, 17:57
Try some of these ...

POKE 53272,21 switch to uppercase mode
POKE 53272,23 switch to lowercase mode
POKE 53280,C change border color (C=0-15)
POKE 53281,C change screen color (C=0-15)
POKE 646,C change cursor color (C=0-15)

POKE 781,X:POKE 782,Y:POKE 783,0:SYS 65520:Print"Your Message" Prints Your Message at X=ROW Number, Y=Column Number

POKE 214,X:POKE 211,Y:SYS 58732:Print "Your Message" Prints Your Message at X=ROW Number, Y=Column Number

4th February 2012, 18:44
Basically I bought Easy Flash 3 from Retro-Donald, and he was so nice to put a bunch of games on it for me, as I have no way to put games on it (no 1541).

Some examples:

Prince of persia- I see some garbage on the screen, when I move around the character disappears, after a few seconds, game crashes.

Last Ninja 3- Loads of garbage on screen

I have also made my own .crt game collection which Donald has put for me on the cart. I have tested this .crt on an emulator and all work fine. Nearly none work on the C64. Some of these just quit to blue screen, others crash prior to starting the game.

I have run the memory test found in EasyProg which is also on the cart, and it didn't find any issues.

Later today I will try those Poke commands.


---------- Post added at 19:44 ---------- Previous post was at 19:32 ----------

Update, I have ran all those POKE commands and all worked fine.

Anything else to test? The C64 is in such a nice condition I'll cry if something wrong with it :(

4th February 2012, 18:46
Check the condition of the cartridge port. Make sure the gold connectors are bright and clean. If not, try using a pencil eraser GENTLY over them to remove any built up grime and dirt

4th February 2012, 19:32
Is there any difference if the C64 is cold (after some hours without use) ?
Do you have another PSU to test with?

4th February 2012, 19:49
Hmmm no, no difference. I only have 1 PSU... but a guy at work has promised me to lend him his C64 (which he hasnt touched for years), hopefully it still works and I can test the Easyflash 3 cart on his machine (to determine if the problem is with my c64 or the Easyflash). I will also test my C64 with the other machine's PSU.

Sundown, when you tested my C64 did you use the PSU you sent me or another? Just wondering.

PS I will check the cart slot connectors tomorrow morning

4th February 2012, 19:58
I used the one I sent you, I alway test with what I sent.

4th February 2012, 20:01
I used the one I sent you, I alway test with what I sent.

Ah ok, hopefully once I get my friend's C64, I'll be able to settle this :)

But tomorrow I;ll take a look at the cart port (although I'm 99% sure there is nothing wrong with it)

Update: Bad news, my friend's C64 doesnt work - he says he just tried, and he says when he presses a button, for example A he gets two letters instead, for example XC

4th February 2012, 20:20
I would also try cleaning the cartridge port like StrontiumDog (http://www.amibay.com/member.php?u=1441) suggested.
I can imagine not all carts using the same connectors or just some carts making better contact then others

4th February 2012, 20:37
After you do all the exellent stuff already suggested, wich has highest priority, check the health of the mem chips.

You need to google since to many revisions. All mem chips should feel the same, if one of them gets much hotter then ..

---------- Post added at 21:35 ---------- Previous post was at 21:33 ----------

oh... and please check psu voltage ... It is known ..

---------- Post added at 21:37 ---------- Previous post was at 21:35 ----------


5th February 2012, 09:47
I have used the pencil eraser on the cartridge port pins but it made no difference.

I have also sent my .CRT compilation to a guy (not local) who also owns an EasyFlash 3, and he confirms all games worked for him.

By Tuesday I will have tested my EasyFlash 3 cartridge on another C64 (hopefully). That should point to where the problem is.

6th February 2012, 14:52
Today I got another C64 from a friend, and my EF3 worked immediately.

Seems the problem is the C64 - aaargh :(

/me is sad.

6th February 2012, 14:57
Hmm thats not good.
Did you try the other persons power supply on your C64 ?

6th February 2012, 15:25
Yes I did - no difference.