Hi.

I' haven't been posting for a while, but that doesn't mean I am not working on anything 6502 related anymore.
After my first 6502 run I decided to scrap everything and do it all over, but better.

I decided to give it another run, and this time it is all going to be built on proper PCB-s instead of point to point soldering.

I am trying to get a system where I could switch the cpu board with some Intel cpu (I have few 8031 in stock), but then there is the issue with the bus signals.
6800/6502 bus have a r/w and a E (phi2) signals for control, where Intel have wr and rd signals which are already timed.

What would be the best way to set the signals on the backplane? Leave them 6502 style, and then have Intel like peripherals have extra logic to adapt the signal (which is not that hard), or generate the extra wr signal on the 6502 board?

If you have a backplane and want to swap CPU cards between Intel and Motorola timing... either you'll have two flavours of daughterboards, or just one flavour. In the first case, you might allocate signals for both conventions, and the boards use the appropriate one. In the second case, you just need to decide whether the least-effort case is a 6xxx-flavoured system or an 8xxx-flavoured one.

Dajgoro:

Good to here from you. Certainly hope your studies are going well.

Assuming your CCAs might be single functions, I would include the Intel/Zilog nRD/nWR signals on the bus coming out of the CPU card. This would provide the widest possible selection of peripheral which you can use to implement your I/O cards. There are far more devices readily available using the Intel/Zilog bus signalling convention than the MOS/MOT signalling convention.

It is also possible to include the direction pin RnW and the clock (Phi2) in addition to the nRD and nWR strobes without too much effort and wire the peripherals accordingly.

_________________
Michael A.