tepples wrote:
Practically infinite? If you want a scanline IRQ and CHR RAM in a cart for use on North American NES consoles, you have exactly five choices for donor carts (three TGROM and two TQROM), and none of them are exactly dirt-cheap. Only with a circuit similar to that of Color Dreams or a successful reverse engineering of 10NES can we have the complete freedom of cart design that Michel "Bananmos" Iwaniec and others have been claiming is the core of NES development.
This is why you design your own PCB... then you can use ANY i.e. MMC3 cart to make your games. Just buy the absolutely cheapest MMC3 containing carts you can get your mitts on. Remove the MMC3 and lockout chip, and solder them to your new board. As a bonus, you do not have to dick with rewiring the boards to accept EPROMs or flash ROMs- you can design your board to suit exactly what you need, including things like WRAM or CHR RAM. As a bonus, you can even do cute things like bank 32K of CHR RAM, which is not possible on any MMC3 cart.
Removing the chips isn't too difficult if you have a dedicated desoldering tool. The MMC3 is surface mount, so removing it is very simple- I use a heat shrink gun for this. I heat the chip up, and use a knife to just "pop" it off the board. The lockout chip is then desoldered using the desoldering
iron.
Since you won't be caring too much about the PCBs though, you can go to a much cheaper and faster destructive desoldering practice... the blowtorch. This will heat the pins up at once making removal a cinch. If the boards have WRAMs or whatever you can save these too and put them on your own carts. To remove the MMC3, you'd heat the board from the *bottom* then slide the chip off with the knife blade once the solder was molten. Shouldn't take more than 1-2 minutes a board to strip them.
You could save the ROMs too, but they are pretty worthless and I'd just leave them on and throw them away with the boards most likely once the lockout chip, RAM(s) and MMC3 were removed (and any 74HC32 or other useful chips).
