A GameShark code for these consoles is written in the format ttvvaaaa. tt specifies the code type and VRAM bank, which is usually 01. vv specifies the hexadecimal value the code will write into the game's memory. aaaa specifies the memory address that will be modified, with the low byte first (e.g. address C056 is written as 56C0). The GameShark hooks into the vertical blank interrupt to write the given value to memory every frame. Up to 15 codes can be active at once.
Oh, and based on the example address given, the address given in the code is based on System Bus address instead of WRAM. So System Bus address C056 = WRAM address 0056, for example.
Just use this to determine what value should be written at which address, and enter the cheat directly.
There was another topic on this forum about it as well: http://tasvideos.org/forum/viewtopic.php?t=13991
FractalFusion is correct.
Whilst this doesn't pertain to your question directly, I thought I'd quickly add that it's the same deal for N64 Gameshark codes. The following code for instance, 802808DF 0000, would be activated by setting a value of 0000 in the address 2808DF in the RDRAM.
I'm not as active as I once was, but I can be reached here if I should be needed.
