How do I get these games to work???

Tonks · Post by **Tonks** » Sun Jul 11, 2004 8:18 am

I recently came across a heap of tapes that have cartridge games on them. (eg, Jelly Monsters, Shamus, Raid on Fort Knox) Problem is, I cannot get any of them to load up properly. I always get a load error. I have tried loading them up with different memory expansions, but nothing seems to work.

Does anyone have any suggestions on how I might get some of these games to load? Do I need to type in a special SYS number? If so, how do I know what to type in?

Any suggestions would be appreciated.

Leeeeee · Post by **Leeeeee** » Sun Jul 11, 2004 9:29 am

It's been a while since I've done it but ISTR it goes like this ..

Do LOAD "filename",1,1 to load the image into RAM at it's original location (usually $A000, you will need RAM here for this to work).

Once it's loaded press RUN/RESTORE to start it, assuming it's an autostart cart.

Lee.

Boray · Post by **Boray** » Sun Jul 11, 2004 12:28 pm

The games may not have been saved from the correct memory position, (none of the ones I have on tape is), so to be safe, do this:

poke43,0:poke44,160
load

(for block 5 ($a000) where you need to have 8k of memory.) If you have a Commodore 8k cart, then there are switches inside to put the cart at that address.

to run:
sys64802

Maybe Jelly Monsters has a different start sys. I will check that later.

/Anders

Boray · Post by **Boray** » Sun Jul 11, 2004 12:33 pm

The start sys for Jelly Monsters is SYS40992

If the games not are cracked, then there might be a copy protection. (I think there is one on Shamus). If that is the case, then you need a read/write switch on your ram cart. Put it to read/write, load the game, put it so read only, then sys64802 to start.

/Anders

Boray · Post by **Boray** » Sun Jul 11, 2004 12:38 pm

But if you get a LOAD ERROR message, then it probably is the tape or tape recorder that is something wrong with. You can always try to clean the read/write head with a little alcohole.

/Anders

carlsson · Post by **carlsson** » Mon Jul 12, 2004 12:48 am

Isn't the "start" address the same for all auto-starting carts, i.e. $A020 (40992) or whereever it is? If I remember correctly, the ROM image format contains two or three vectors for hard and soft restart.

Leeeeee · Post by **Leeeeee** » Mon Jul 12, 2004 6:46 pm

For an autostart cart the first word is the code start vector, the next word is the warm start (restore) vector and then the autostart ident string.

Bytes #9 onward are whatever is put in them.

The best way to start an autostart ROM from BASIC is to do SYS 64812 which calls the kernal autostart vector jump.

Lee.

Boray · Post by **Boray** » Tue Jul 13, 2004 3:05 pm

I just know that most games starts with sys64802 but that some that I have on tape has a different sys written by the name in my tape book. I always thought that someone had found a "different" sys for bypassing the copy protection or something. For example,
Poker has SYS42743,
Road Race has SYS40986,
Alien has sys44615.
Jelly monsters, Jupiter lander, star battle and mole attack all have sys40992.
Rat Race has a poke: Poke 49151,191. Hmmm... Seems they failed to save the last byte there

/Anders

Leeeeee · Post by **Leeeeee** » Tue Jul 13, 2004 5:23 pm

I just know that most games starts with sys64802

This is the power on reset vector and is the same (almost) as pressing a reset button or powering up the machine. The only downside is that a broken cart image (and some break themselves by trying to overwrite the autostart string) won't work.

For example,
Poker has SYS42743,
Road Race has SYS40986,
Alien has sys44615.
Jelly monsters, Jupiter lander, star battle and mole attack all have sys40992.

All these addresses are, obviously, within the cart area and are probably just using the cold start address that would be found at $A000/$A001 (40960/40961).

SYS 64812 bypasses the start string check and just jumps to the code start address.

Rat Race has a poke: Poke 49151,191. Hmmm... Seems they failed to save the last byte there ;)

Looks like they forgot the SYS as well.

Lee.

Boray · Post by **Boray** » Fri Jul 16, 2004 12:44 pm

I tried to load some cart games from tape today (recorded in 1983), and I got LOAD ERROR on every single one of them. But they work perfectly anyway. Maybe because they are saved from block 3, you awlays get a load error message? I can't remember if this is how it was when I used the tapes in 1987.

Anyway, as I said, they worked fine...

/Anders