My V3 BASIC cart isn't working correctly

Started by zmaster18, June 12, 2014, 10:29:42 am

Previous topic - Next topic

zmaster18

I have 2 V3 carts, one that functions normal and has the guidebook that I have listed online, and another one that's just the cartridge that I own in my personal collection that has issues. First of all, when I start the system on there's a message in katakana saying to put the switch in the off position. I get this message regardless of whether the switch is in the ON or OFF position. The command prompt finally comes on after I play with the switch for a minute. Maybe the switch needs to be resoldered or something.

My next issue is when I right any program, it won't run. It says:

?SN ERROR IN 24672

It doesn't matter how small of a program, it won't run anything. I believe something has happened in the carts memory after I pressed the F function keys and played the built in games. I think the previous owner put some kind of memory-damaging command by mistake or intentionally, I don't know :P

So here's the question: Can I go to the memory address and rewrite what seems to be a missing piece of data? And another question, can I erase the 4 built in games and use the free data from where they were held?

P

June 12, 2014, 01:28:59 pm #1 Last Edit: June 12, 2014, 01:52:49 pm by P
Can you really physically damage the memory area with a command? It sounds like the cart is damaged to me, or just dirty pins as with all other games. I would first try clean the pins with isopropyl alcohol, and if it doesn't help I would check connections of the switch and other things with a multimeter.

The previous owner's program shouldn't be left in memory if you remove the batteries. What happens if you type NEW? That should also clear the program memory.

Quote from: zmaster18 on June 12, 2014, 10:29:42 am
Can I go to the memory address and rewrite what seems to be a missing piece of data?

Yes you can write whatever you want to any address using the POKE command. But it won't help you in this case. Just clear the memory.

Quote from: zmaster18 on June 12, 2014, 10:29:42 am
can I erase the 4 built in games and use the free data from where they were held?

No they are burned into the ROM and can't be permanently cleared. Only the RAM area between $6000-$7FFF that comes right before the ROM (the ROM starts at $8000) can be used for saving. Actually only $6000-$6FFF is marked as "User RAM" at page 126 in the manual so I'm not sure if you can use the remaining $7000-$7FFF (which is marked as "unused region") as well. Probably not.

Edit: I just did some calculations and $6000-$6FFF should cover 4095KB (which is how much saving memory V3 has). So the memory areas marked as "unused region" simply doesn't exist on the cart.
Check the V3 manual translation in my signature. Pretty much all the basics are translated already.

zmaster18

Ok, now this cart is working. I resoldered the wires that attach to the switch on the cartridge a long time ago and now it works perfectly. Weird...

P

I guess the old solder had become bad, which made the cart act like the switch was always in ON position.

Glad you got it working again!

zmaster18

May 20, 2015, 12:01:30 pm #4 Last Edit: May 21, 2015, 10:43:43 am by zmaster18
Someone just buy this extra V3 cart from me... I don't need another one. :P

Post Merge: May 21, 2015, 10:43:43 am

I found another problem with the cart when I tried using the BACKUP command to save to battery backup. After saving and testing a program, some lines of code became random numbers. I looked in the battery compartment and saw some blue corrosion. I used some vinegar and alcohol to clean it up again and now it saves programs perfectly.