Built in games

Geebs61 · Post by **Geebs61** » Fri Sep 24, 2004 2:37 pm

After reading about the 512 multi cart, I started thinking. Is it possible, to make games built in to a system? Any type of system. I ask because I have a 7 yr old cousin who wants me to build him a portable but I know he doesnt have any games. What about replacing games on the NOAC? Is that possible?

HK-47 · Post by **HK-47** » Fri Sep 24, 2004 2:41 pm

I dont see why not. You could just hook up the pins from the cart port (on the noac) to the eprom or whatever they're called. Overall Im sure you could get it working somehow.

Post by **gannon** » Fri Sep 24, 2004 2:52 pm

That's sort of what I was going to do with my .nsf player, you might even be able to make a switch for internal or ext. carts

HK-47 · Post by **HK-47** » Fri Sep 24, 2004 2:54 pm

Yeah that would be pretty cool. Tell us if you make something of the sort.

Geebs61 · Post by **Geebs61** » Fri Sep 24, 2004 2:58 pm

well, first I would need an eeprom reader/writer... and I would beed to know how those work. and I need some eeproms... but I might have some in that hurking box of IC's I have... I wish I knew what all was in there.

HK-47 · Post by **HK-47** » Fri Sep 24, 2004 2:59 pm

Mabye that mindstien guy could program the eproms for you.

Post by **gannon** » Fri Sep 24, 2004 4:38 pm

I have 2 8kb eeproms, but those are way too small for games.

mindstein · Post by **mindstein** » Mon Sep 27, 2004 5:26 pm

Hi I actualy was going to build the 512 cart that I am making into my portable and I designed it that way in the begining. But after I started building the portable I thought that having it in a cart was just as good.

But go ahead and do it. I also had a version designed that had 4 sockets that you can get to from the back of the portable and plug in the real chips from the atari. The socketed version used an old scsi select switch to select between the games.

Anyhow I have prototyped both of them on a bread board and it works great so go for it.

If you use a build in games what you will want to do is isolate one of the ground pins on your cart port and connect it to a pull-down resistor.

I used this method to build in a multi cart into my socketed 6 switcher.

When a cart is NOT in 5v goes to the build in game. When a cart is put in the pulldown resistor shorts the 5v going to the built-in game chip.

The way a pul-down resistor works is you are just shorting positive and negative leads but since they are shorting through a large resistor there is not realy a short.