nesdev.org

* Use two 74'670s to yield four bank registers (he calls them K0 through K3) * The /SYNC output on the 65C02 lets him capture, intercept, and replace opcodes from memory before it enters the CPU. This is microcoded using external ROMs * Forces all stack and direct-page accesses to only bank 0, whil...

Lol this project is like a 6809-6309 equivalent, I wish this was on a chip.... Meaning that the Kimklone upgrade to 6502 is comparable to the 6309 upgrade to 6809? Interesting comparison. BTW it would've been nice to implement the KK as a chip, but unfortunately CPLDs and FPGAs didn't exist back th...

Can the 68000 shift a register in 1 cycle? No it can't! Can the 68000 multiply in 10 cycles? No it can't! Can the 68000 add an immediate in 2 cycles? No it can't! Heheheh... I'm a big 6309 fan, too. I've only ever coded for 6809, though. 68000 looks nice; I wanna try that as well. But as for all th...

hello, fellow 6502 lovers Some of you folks will be interested in this project. It is a co-processor that extends the 65c02 architecture , and it provides new registers and new instructions that are fully as fast and flexible as those of the legacy CPU. One of the main benefits is a 16 MByte address...

The byte on the stack that holds the status flags also holds a flag indicating whether it was a BRK or IRQ. Yes, this is putting it quite nicely. SOMETHING gets pushed to stack, but it's not a Flag in the same sense as Carry, for instance. It is the signal called D1x1 on that big schematic. There i...