Odd Venture PCB

[toymailman]

I was taking apart some Coleco carts that will be sent to Al and noticed one of the Venture boards has an extra chip on it. It seems to play the same as the regular one. Does anyone know why it was made this way?

 

[jaybird3rd]

The additional chip is a 74LS04 inverter, which you would need if you were to use an EPROM on a standard 2600 cartridge board instead of an ordinary mask ROM. My guess would be that the board with the inverter is the earlier of the two, and that they switched to a cheaper, mass-produced ROM later.

[Nukey Shay]

I'd guess the other way around...i.e. Eprom chips sometimes used to make up the difference if production numbers of mask Roms turned up short.

[runpie]

I have a donkey Kong jr pcb missing the top half of the board. Does somebody have a working cart they could take a picture of so I can rebuild the pcb? (front and back) Also I think I would have to get the hex inverter chip as well.