Help identifying cartridge

[manterola]

Any ideas? Maybe some kind of cartridge similar to "The Pill".

The internal IC is a CD4069.

Thanks 👍 👍 👍 

 

[Rybags]

Possibly.

The CD4069 is an inverter so just takes inputs and reverses the level.

The presence of RD4 and RD5 signals mean that an operation to the cartridge area (2 x 8K banks $8000 and $A000) will be directed to the Rom rather than system Ram.

You need those signals to be switchable so you can do the initial write to Ram of the cart image.

Once switched on, in theory you could just take the R/W signal and invert it (write = active low) then output it to RD4 and RD5 which would signal presence of a cart and prevent the Ram being overwritten.  A read operation turns those lines off so that the Ram will supply the data.

 

You can use the pinout here to verify if that is the case:  https://atarimax.com/jindroush.atari.org/acarts.html

[phaeron]

It does look like it switches RD4 and RD5. Is the switch a two-position or three-position switch?

 

[manterola]

It is two position switch. And yes, the IC is just a bunch of inverters. So maybe it is just a "The Pill" clone.

Edited June 11 by manterola