Seems you're attempting a type of "blind interface" with the FT245? Not sure if this will help but here's a few basic microcontroller "blind interface" functions where the microcontroller controls the clock, memory, and reset on the 6502 system and uses push() and pull() clock cycle functions to convey instructions and data to/from the 6502 over the data bus;
void cpu_reset(); // **************************************
{ reset_pin = 0; // R65C02 reset sequence *
pull(); // *
pull(); // *
reset_pin = 1; // *
pull(); // *
pull(); // *
pull(); // *
pull(); // *
pull(); // *
push(0x00); // FFFC:00 reset vector lo *
push(0xC0); // FFFD:C0 reset vector hi *
} // **************************************
void Wr_Byte(u16 addr, u8 data) // **************************************
{ push(0xA9); // lda <imm> *
push(data); // " *
push(0x8D); // sta <abs> *
push(addr.lo); // " abs address lo *
push(addr.hi); // " abs address hi *
pull(); // " 6502 write op *
} // **************************************
byte Rd_Byte(u16 addr) // **************************************
{ push(0x4C); // jmp <abs> avoid page boundary *
push(0x00); // " abs address lo *
push(0xC0); // " abs address hi *
push(0xAD); // lda <abs> *
push(addr.lo); // " abs address lo *
push(addr.hi); // " abs address hi *
return pull(); // " return value on bus *
} // **************************************
Basically, a pull() clock cycle turns memory on for a 6502 memory read or write operation while a push() clock cycle turns memory off and allows the microcontroller to supply an instruction or data to the 6502. A clock cycle always starts and ends in the high state. Of course after using the microcontroller & "blind interface" to load RAM or burn a Flash ROM via hex file or X-modem, it can completely disconnect from the 6502 system.
I've been trying to figure out how to implement something similar with the FT245 but "no joy", so far.
I won't bore you or other members with details unless you feel it may help...
Regards...
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