16K cart with multiple rom images

[redman]

Hello all,

 

I would like to make a cart that will hold a lot of 16K game images. Through the years, I've downloaded a lot of 16K cart dumps that I want to use. All the Atari 16K carts that I've looked at have 2 8K chips on the board so it looks like a straight replacement with a 16K file won't work. I have a Miner 2049er cart that I think is 16K and has the 2 chips socketed. My plan is to divide the 16K cart dump images in half and use 2 large eproms to hold each 8K high and low image. I would use double pole switches to simultaneously switch the 8K pieces. One eprom would hold all the high parts and the other the low parts. Does this sound like it will work? I think that it would be hard to stuff the 2 eproms and associated wiring with the pullup resistors etc. into the Miner cart so I would probably put the board from the Miner cart into a bigger box and run a ribbon cable to something like and old Basic cart that would be gutted just to use the contact fingers. What do you think? Thanks for listening.

 

Redman

[mimo]

If you want an easy way to have a multicart just buy a 1 meg or 8meg Maxflash cart from Atarimax.com

[Rybags]

I think whether these things work can depend on the cartridge board.

 

IIRC, you have 2 Chip Select lines going to the cartridge, and they're inverted from normal address lines (?)

 

My guess is you'd need to OR them together to get a CS input for your Eprom, and invert them to give addresses A12 and A13, although I don't see that as 100% necessary since you could create your Rom image ordered to cater for that.

[redman]

Hello all,

 

I would like to make a cart that will hold a lot of 16K game images. Through the years, I've downloaded a lot of 16K cart dumps that I want to use. All the Atari 16K carts that I've looked at have 2 8K chips on the board so it looks like a straight replacement with a 16K file won't work. I have a Miner 2049er cart that I think is 16K and has the 2 chips socketed. My plan is to divide the 16K cart dump images in half and use 2 large eproms to hold each 8K high and low image. I would use double pole switches to simultaneously switch the 8K pieces. One eprom would hold all the high parts and the other the low parts. Does this sound like it will work? I think that it would be hard to stuff the 2 eproms and associated wiring with the pullup resistors etc. into the Miner cart so I would probably put the board from the Miner cart into a bigger box and run a ribbon cable to something like and old Basic cart that would be gutted just to use the contact fingers. What do you think? Thanks for listening.

 

Redman

 

Hello again,

 

I see that the AtariAge store sells this board - (8-bit 8K/16K PCB $8.50). Has anyone bought and used one of these? Do you think that the 16K cart dumps that are available would work? I've attached a list of 16K dumps that I have accumulated through the years. TIA.

 

Redman

16Kdumps.txt

[Rybags]

Well, if you make a cart with 16K banks, then 8K games will have 8K wasted with each one.

 

Unless... wonder if you can employ logic to select banks still on 8K boundaries but appear as 16K, then there would be no wastage and you can mix/match sizes.

 

Also note - many 8K games are in fact smaller. e.g. Missile Command is only 6K, Gridrunner IIRC is 4K and you have others like TicTacToe and Computer Chess that I'm pretty sure are 4K or less.

Some have just 00s in the ROM, others might be just 4K ROMs that appear twice identically at page $A0 and $B0.

 

From that list... dunno. A good number of the BINs would be > 16K. Just not bothering with anything >16K makes a start.

For the rest, you could test in the emulator.

But, AFAIK about the only 16K ROMs out there commercially that didn't map contiguously were the OSS Language carts.

Edited March 22, 2009 by Rybags

[sup8pdct]

I have done about 3 of these.

What I did was to split each 16K game in half. Then append all the upper half to gether, same with the lower half makeing sure that each game half aligned with each other. I then burnt 2 27512 eproms, marking each low and high.

I then got a 16K atari cart, modded it to take 2 eproms. I soldered resistors to the upper 3 address lines of both eproms to ground.

Got a 4 way dip switch, made one side at +5v, the other side soldered to both eproms with wires.

Had to set up a list on the front of the cart for the dip switch combo for each game.

Also did the same for 8k cart games as well.

 

James

 

 

 

Hello all,

 

I would like to make a cart that will hold a lot of 16K game images. Through the years, I've downloaded a lot of 16K cart dumps that I want to use. All the Atari 16K carts that I've looked at have 2 8K chips on the board so it looks like a straight replacement with a 16K file won't work. I have a Miner 2049er cart that I think is 16K and has the 2 chips socketed. My plan is to divide the 16K cart dump images in half and use 2 large eproms to hold each 8K high and low image. I would use double pole switches to simultaneously switch the 8K pieces. One eprom would hold all the high parts and the other the low parts. Does this sound like it will work? I think that it would be hard to stuff the 2 eproms and associated wiring with the pullup resistors etc. into the Miner cart so I would probably put the board from the Miner cart into a bigger box and run a ribbon cable to something like and old Basic cart that would be gutted just to use the contact fingers. What do you think? Thanks for listening.

 

Redman

[ndary]

simplest way to do what you are looking for is to take a 16k XE (gray case) cartridge... like junglehunt or joust.. then to disasseble its ROM and replace it with a 1meg (27c8001 eprom), using small dipswitches to change the chip address line you can place 64 x 16k images on a cartridge..

 

Nd

[Shawn Jefferson]

Unless you are doing it more for "fun", the Atarimax flash cartridges will be so much easier. Of course, there is a cost associated with them that may be too high. The neat thing is that you can reflash them with whatever you want.

 

For instance, I just released Ultima II for the 8Mb Atarimax flashcart over at www.atarimax.com forums....

[redman]

simplest way to do what you are looking for is to take a 16k XE (gray case) cartridge... like junglehunt or joust.. then to disasseble its ROM and replace it with a 1meg (27c8001 eprom), using small dipswitches to change the chip address line you can place 64 x 16k images on a cartridge..

 

Nd

 

That's just about what I'm going to do but I'm going to use 2 27C801's piggyback style to hold 128 images. The cartridge shell may have to be hacked though. I sent away for 2 of the cart boards that AtariAge sells with 28 pin sockets ready for 16K eproms. Can't wait til they arrive. Thanks for the input.

[redman]

Unless you are doing it more for "fun", the Atarimax flash cartridges will be so much easier. Of course, there is a cost associated with them that may be too high. The neat thing is that you can reflash them with whatever you want.

 

For instance, I just released Ultima II for the 8Mb Atarimax flashcart over at www.atarimax.com forums....

 

Yeah, it's for the fun of it. I love hardware projects. I've got an Atarimax flash cart and could never get it to work.