<I was firstly thinking of putting this into a PC case, since the Why? <keyboard is external anyway. But I was reading the CP/M manual <(pretty shallow), and it mentions a 16-user capability and password <protection. Well the 16 user thing is not multiuser it's a way of diving up the directory into 16 distinct areas as CP/M didn't have subdirectories. Password protection? There wasn't any as part of CP/M. How does this work and how secure is it? Also, would you <say that the Z-80 was better than the 8088? It was certainly used <much more... Better... that's a relative term. It was cheaper to use, more software available as it was fully upward compatable with the 8080 (and 8085) that preceeded it and it was there before the 8088. Also as the 8088 got faster the z80 also got faster and added a MMU. I can still build a system using z80 for less than the 8088 and the z80 one will be easier to program. If the program gets larger than fits in the 64k space then the competition becomes a bit more fair. Still segmented space is pretty ugly and a paged MMU on z80 is very easy to do. Or better yet a z180 (64180) which is a z180 with MMU, 2 serial ports and a DMA all on one chip (and still cheaper and faster than a bare 8088 in 1985). The z180 also offered something the 8088 line never had which was a compatable highly integrated version as the 8088 needed several parts around it to use effectively and the '188 was an odd duck compared to the 8088. So for the 8088 comparison the z80 was hard to dislodge. It really took the 386(32bits) to make a real impact. Z80 space was characterized as developing, it was inexpensive to develop around, there were lots of similar and competing systems (both a blessing and curse), tons of cheap to free software, offered sufficient compute power and friendy to program in assembler. The only other chip to be as persistant, easy to use and popular was the 6502. I might add that both were quite popular in the instrumentation and control sytems field. Tidbit... the z80/z180 is still in production and the cmos z80s182 runs at a screaming 20mhz internal clock (roughly 2-4mips processing speed) and can come to a complete stop, using only microwatts of power in that mode. I have a z180 at 9.8mhz and it's quite fast for text apps and is usually waiting on the SCSI hard disk system (xybec/st251). Allison