On Fri, 10 Feb 95 9:22:56 GMT, Mr Andrew M Gale said: > > [ nb 'A Z8108 internally clocked at 24Mhz linked to a 6Mhz bus']
> Actually, I don't even know if you need to worry about tying > the Z800 (can you actually still buy them?) clock to the SAM > clock - the ASIC is going to insert wait states anyway, and > its going to tie those wait to its own 6MHz clock. Precisely what I thought. The minimum amount of time taken by a Z80 instruction on the Sam in 6MHz T-states is 4 times the number of RAM accesses (and that's with the screen turned off). If all you are doing is replacing the Z80 by a Z_something_else then instructions which have a lot of logic and a little memory access (like ADD HL,BC) will speed up, but most instructions (like NOP) will hardly speed up at all unless you store them in ROM or in extended memory. imc
