Recycled 2600 PCBS?

[Shawn]

Hey All,

 

If I wanted to recycle some of my dirt common games to use for homebrew projects is it as simple as taking a 4k game removing the rom and resolidering on an new 4k EPROM? Or 8k game with 8k EPROM and so forth? The more simple the answer the better please.

 

I'm just trying to budget my money with getting into making my own games as I have bought a new EPROM burner and a few EPROMs and I am just trying to see if I can cut any corners and where I can cut them like recycling some game PCBs.

If not I'm just gonna have to buck up and buy all of them from the AA store I just wanted to see if I am able to save a few bucks and maybe not have to buy as many boards right off the hop.

 

Thanks For Your Help,

 

Shawn Sr.

[supercat]

If I wanted to recycle some of my dirt common games to use for homebrew projects is it as simple as taking a 4k game removing the rom and resolidering on an new 4k EPROM? Or 8k game with 8k EPROM and so forth? The more simple the answer the better please.

954359[/snapback]

 

Some third-party games use two chips, of which one is a 24- or 28-pin ROM. On most of those, the ROM may be replaced by another of the same pinout to play a 4K game. Note that some carts will use the top half of a 2764 and others will use the bottom half, so you'll have to ensure that your file is loaded appropriately.

 

None of the rarity-one games will work for this, but I think some rarity-two ones will. I don't think any rarity-twos will support bank-switching, though.

[jsoper]

Using a standard eprom requires you to add a 7404 or transistor to invert the A12 signal.

[Shawn]

I think I'm just gonna buy some new boards instead. Too deep for me just yet. so wit the new boards from the AA store, tell me if this is correct:

 

Burn a 4k game onto a 2732 4k chip (is there any special way I have to do this?), use a 4k assembled board from the AA store, solider the EPROM on the board and slap it into my ATARI.

 

To simple? Or am I getting close? I ask as I just bought a EPROM Programer and it should arrive in about a week so I want to get all the know how into me I can before it arrives.

 

Shawn

 

P.S. All the help is SO greatly appreciated. I am in debt to your kindness of sharing your know how fellas!!

Edited October 26, 2005 by silver_surfer

[Bruce Tomlin]

I've converted my share of Pac-Man boards, with a "flipped-bug" 7404 on the solder side of the cart, and it's a lot of work. Even more work because they use a 2532 pinout. That being said, once it's tested and working with a socket, you don't have to keep modding boards. For one or two socket carts, it's easier for me to make my own.

 

But I'd go with a Pixels Past board if I were you. The main downside is that if you want to do a 4K game, you have to use a 2732, rather than half of a more common 2764. Also, the GAL chip in the bankswitched version needs different programming for different sizes.

 

And you probably want at least one socketed board. It's a bit of a pain to desolder the chip every time you find a bug.

[Shawn]

I've converted my share of Pac-Man boards, with a "flipped-bug" 7404 on the solder side of the cart, and it's a lot of work.  Even more work because they use a 2532 pinout.  That being said, once it's tested and working with a socket, you don't have to keep modding boards.  For one or two socket carts, it's easier for me to make my own.

 

But I'd go with a Pixels Past board if I were you.  The main downside is that if you want to do a 4K game, you have to use a 2732, rather than half of a more common 2764.  Also, the GAL chip in the bankswitched version needs different programming for different sizes.

 

And you probably want at least one socketed board.  It's a bit of a pain to desolder the chip every time you find a bug.

954471[/snapback]

 

 

So, I'm gonna get some new boards from the store I know that for sure now. But what do you mean Bruce by saying I have to use a 2732 rather than half of of a 2764? Isn't the 2764 an 8k chip? Are you just saying it's easier to get ahold of the 2764 chips than it is to get 2732 chips?

 

Also the GAL chip you mentioned needing different prgramming on the bankswitched version of the New boards prending different sizes means if its a 8k game the GAL needs to be programed a certain way where as if it's a 16k or 32k, game it needs to be programmed acordiingly to there respective sizes also correct?

Edited October 26, 2005 by silver_surfer

[Albert]

So, I'm gonna get some new boards from the store I know that for sure now. But what do you mean Bruce by saying I have to use a 2732 rather than half of of a 2764? Isn't the 2764 an 8k chip? Are you just saying it's easier to get ahold of the 2764 chips than it is to get 2732 chips?

The 2732 is a 24-pin part and the 2764, 27128 and 27256 parts are 28-pin chips. For some time it wasn't any more difficult to get 2732 chips than 2764 chips, but recently it has become more difficult to find 2732 parts. Not very difficult, mind you, but they definitely have been getting scarcer and more expensive. At any rate, the 4K board is designed for a 2732 and will not work with a 2764. Nor could you even fit a 2764 part on the board.

 

Also the GAL chip you mentioned needing different prgramming on the bankswitched version of the New boards prending different sizes means if its a 8k game the GAL needs to be programed a certain way  where as if  it's a 16k or 32k, game it needs to be programmed acordiingly to there respective sizes also correct?

That is correct. Doing it this way allowed us to use the same design for 8K, 16K, and 32K boards, with the only difference being the way the PLD is programmed and the type of EPROM used (2764, 27128 or 27256 respectively).

 

..Al

[supercat]

Also the GAL chip you mentioned needing different prgramming on the bankswitched version of the New boards prending different sizes means if its a 8k game the GAL needs to be programed a certain way  where as if  it's a 16k or 32k, game it needs to be programmed acordiingly to there respective sizes also correct?

That is correct. Doing it this way allowed us to use the same design for 8K, 16K, and 32K boards, with the only difference being the way the PLD is programmed and the type of EPROM used (2764, 27128 or 27256 respectively).

954501[/snapback]

 

If you expand a 4K bin to 8K, 16K, or 32K, you can use the 8K, 16K, or 32K boards with it (using a 2764, 27128, or 27256). Actually, if you do the data properly, you can use a 27256 for any size game (in an 8K, 16K, or 32K board).

 

To double the size of a .bin file, do

copy /b oldfile.bin + oldfile.bin newfile.bin

This will convert 4K to 8K, 8K to 16K, or 16K to 32K.

 

Once expanded like that, all 4K bin will play in any size boards.

Many 8K, 16K, or 32K bins will work on any "size" board that's at least as "big" as the bin, but some bins are picky and will only work in the "right" size board. But any size board will work with 27256's if you expand the bin files to 32K as indicated above.

[Shawn]

Well I just made my purchase from the AA store. I got:

 

16k assembled board w/socket

16k assembled board

8k assembled board x2

8k EPROM x2

16k EPROM x2

Extra 28 pin socket

32k EPROM

 

I think this will get me started well. In case your wondering the 32k EPROM is for a 7800 board I already have