EDSAC on your desk.

< We just to joke that Z80EMU on a Pentium was faster than any Z80 process < you could actually buy, I wonder if it wouldn't be feasible these days t < create a 38 pin I/O port and build an "ICE" in software... < --Chuck thats a tall claim as the z80 is available up to 20mhz and z180s to 33mhz. Then you can also use he Z380 is z80 native mode (it uses fewer clocks per instruction than any other z80) at 20mhz (faster are supposed to exist.). I am in the process of bringing up a Z280 at 12.5mhz (with 16bit zbus) and I expect that with it's instruction cache and fast ram there will be a new level of CPM performance comming. since I have a z80 system that runs at 8mhz (no waits!) and MYZ80 on a 486dx2/66 and the 486 is faster on emulated disk IO (inherent caching) but about the about the same as the 8mhz system otherwise. The disk differences are due to the type of interface SCSI-1 vs SCSI-II and size of buffers. Emulators have their place. One is allowing cross platform code development and testing and the other is allowing access to archetectures that are scarce or unusual. Allison