Zach's Projects

All you need is a DPDT switch connected to the chip enable pin (A12) and a couple of resistors. This will allow you to float the bus on one or the other cart, so you can have them both plugged in at the same time.

All you need is a DPDT switch connected to the chip enable pin (A12) and a couple of resistors. This will allow you to float the bus on one or the other cart, so you can have them both plugged in at the same time.

Thanks for the quick reply. I'm not sure I understand what you are describing. Would it need two cartridge slots? If not, how could both the cartridge and the dumper board connect to the VCS?

All you need is a DPDT switch connected to the chip enable pin (A12) and a couple of resistors. This will allow you to float the bus on one or the other cart, so you can have them both plugged in at the same time.

Thanks for the quick reply. I'm not sure I understand what you are describing. Would it need two cartridge slots? If not, how could both the cartridge and the dumper board connect to the VCS?

You could do it one of two ways. One, you could build a board with two slots on it, one for the batari dumper cart and one for the cart to dump. Two, you could hack a slot onto an AA board.

 

On second thought, you just need a SPDT switch. You have 3 connections on a switch like this. The center connects to A12 coming from the 2600. Each side of the switch connects to A12 on a slot or board, and also to a resistor running to GND.

 

If the switch is in one position, only one cart is enabled at a time. It doesn't matter that everything else is connected - only one chip will have access to the bus at any time.

Thanks Fred. I added a new diagram based on your description. Does that look more like what you are talking about?

 

I only drew the first 12 lines for simplicity's sake. Also, I didn't draw the connections to the Atari board. It'll be easier to trace which holes connect to which pins once I remove the chip. Also, I set aside resistors and GND for a later time. For now, the next step will be to buy a soldering iron and learn how to use it. If that works out, I'll come back here to ask for help selecting resistors.

If anyone is wondering, I am still working on this. I bought a soldering iron recently and managed to fuse together a Y-shaped wire. I was a bit surprised when smoke came out of the solder, but I guess there is more in it than metal.

 

So far I have a soldering iron, 25 ft of wire, and an SPDT switch. What I still need to get is a cartidge slot and a 4K ROM board. I will order the former when I get my next paycheck. If I get a desoldering pump, it shouldn't be too hard to make the latter from a Pac-Man cart.