Atari 2600 menu cartridge ROM

[dg67]

Hi,

I've all I need (Atariage socketed cartridges, blank eproms and a Willem programmer) to burn games for Atari 2600.

 

I just like to know if there's some 8k, 16k or 32k ROM image with a built-in game menu (loaded in the first 2k) allowing me to run games loaded in next ROM memory addressed space.

In the ROM image I can store several 2k (or 4k) ROM games, just after the game menu program.

 

I can try to explain it better, I know it's hard to explain:

 

When I power the Atari 2600 on, it should load a game menu, where different loading options ("Run game 1", "Run game 2", and so on) are displayed.

If I choose the "Game 1" Atari should load the first game in the ROM.

If I choose the "Game 2" Atari should load the second game in the ROM.

 

And so on...

So I can easily build a menu-driven multigame cartridge.

 

I guess a 2k ROM should be enough to program a game loading menu.

on a 8k ROM a maximum of three 2k games (or one 2k and one 4k) could be loaded.

on a 16k ROM a maximum of seven 2k games (or three 4k) could be loaded.

on a 32k ROM a maximum of fifteen 2k games (or seven 4k) could be loaded.

 

Is it possible to write a ROM cartridge like that one?

If some of you already wrote it this please post it

 

Thanks!

dg67

[toiletunes]

I've thought about that before- it would be interesting to have, say, all the playaround games on one cart- or all the atari kids games or whatever. I know a cuttlecart would do the same thing, but it would still be nifty.

[dg67]

I've thought about that before- it would be interesting to have, say, all the playaround games on one cart- or all the atari kids games or whatever. I know a cuttlecart would do the same thing, but it would still be nifty.

 

Of course, the Atariage Socketed Cartridges can handle up to 32k ROMs (on a 27c256 chip), so no more than eight 4K Roms can be easily stored, including the game menu program.

[+batari]

Yes, it's possible but not quite how you suggest. The 2k games are usually assembled to run at $F800-$FFFF so you can only use one per bank (unless you disassemble and modify them, but that's difficult to do.) I wrote a simple menu in batari Basic for eight 2k games for another project but it never got used, and I'd be happy to share it, if I can find it, but it's very simple (just select a number with the joystick.)

 

The other wrinkle is your cart needs to start up in the menu bank all the time, otherwise it would just run a random game and rarely the menu. Some ways around this are to modify the reset vectors for each game, and code in the lower 2k to jump to the menu bank. Another way is to only use AA boards that have the Atmel PLDs as these reliably start in the first bank. The Lattice PLDs don't seem to.

 

Now if you are using the Atmel PLDs, you could probably get away with 4k games in each bank, though you'd be limited to 7 of them with 32k.

[A.J. Franzman]

Several multicarts such as that already exist, with 2-5 games each, readily available in Rom Hunter's collection. Most of them are by HES, with one Atari prototype and two BitCorp carts filling out the total. Most other multicarts require special hardware, such as switches to select the bank, or a mechanism which advances a counter each time the power is cycled off and back on.

Edited December 10, 2010 by A.J. Franzman

[dg67]

Yes, it's possible but not quite how you suggest. The 2k games are usually assembled to run at $F800-$FFFF so you can only use one per bank (unless you disassemble and modify them, but that's difficult to do.) I wrote a simple menu in batari Basic for eight 2k games for another project but it never got used, and I'd be happy to share it, if I can find it, but it's very simple (just select a number with the joystick.)

 

The other wrinkle is your cart needs to start up in the menu bank all the time, otherwise it would just run a random game and rarely the menu. Some ways around this are to modify the reset vectors for each game, and code in the lower 2k to jump to the menu bank. Another way is to only use AA boards that have the Atmel PLDs as these reliably start in the first bank. The Lattice PLDs don't seem to.

 

Now if you are using the Atmel PLDs, you could probably get away with 4k games in each bank, though you'd be limited to 7 of them with 32k.

 

I'm using 27xxx Eproms. Anyway I will happy to test your BAtari Basic program (and some 2k game) if you can send the .bin to me and the way to attach the Roms to it.