how to create an on/off switch on a cart

[Marius]

Hi.

 

I want to make a cart which stays in the atari, so it will not be removed. But most of the time I want the atari to act like there is no cart connected. I know there is a certain pin x + pin y connection which I have to cut (and place a switch between those points) to realise this, but I'm not sure of this is a safe/legal way.

 

Does anybody know which connections I have to cut and put a switch in, or is this not a good way, and is there a better way?

 

Thanks

Marius

 

p.s. It is for a cart which carries the Sio2IDE FDISK program. I only want to boot the cart when I need that program, but I don't want to remove the cart all the time.

[dinosaur]

Hi.

 

I want to make a cart which stays in the atari, so it will not be removed. But most of the time I want the atari to act like there is no cart connected. I know there is a certain pin x + pin y connection which I have to cut (and place a switch between those points) to realise this, but I'm not sure of this is a safe/legal way.

 

Does anybody know which connections I have to cut and put a switch in, or is this not a good way, and is there a better way?

 

Thanks

Marius

 

p.s. It is for a cart which carries the Sio2IDE FDISK program. I only want to boot the cart when I need that program, but I don't want to remove the cart all the time.

 

There was an article in the old "Current Notes" about someone putting switches in a SpartaDos X cart so that he could leave it in place and turn it off.As I remember,it required two toggle switches (one on each side)

 

I believe that the author wanted to use an AtariWriter cart this way.

 

If I can find the article,I will scan it and send it to you...might take a while to find it.

[Nukey Shay]

If the purpose is to create a dummy cartridge...so you can load cartridge binaries and then flip the switch to keep the memory that the program occupies in "read-only" mode (defeating copy-protection schemes that involve writing to the cartridge address space), this might help...

 

http://www.atariarchives.org/cfn/05/07/0039.php

[Rybags]

This is just an educated guess, but I'd say that disabling the two Chip Select lines should be sufficient to disable the cart.

 

Although I don't know if that will also cause the computer to give precedence to RAM over the cart... how is a cart detected? Current drain?

[candle]

if memory serves there are s4 s5 (select) and rd4 rd5 lines for this

keeping rd4 and rd5 low should be enought

[+bob1200xl]

The cartridge is detected by asserting RD4 and/or RD5. One is for the lower 8K and the other is for the upper 8K. If you cut the RDx traces on the cart PCB, memory will appear if RDx is open and the cart ROM will be selected (by S4 and/or S5) if RDx is +5v.

 

Bob

 

 

 

This is just an educated guess, but I'd say that disabling the two Chip Select lines should be sufficient to disable the cart.

 

Although I don't know if that will also cause the computer to give precedence to RAM over the cart... how is a cart detected? Current drain?

[candle]

found this by accident, may be of some use, if what Bob said is not clear enought

 

http://ftp.pigwa.net/stuff/collections/ata...ge/FAKECART.HTM