[net.micro] NS Z80 look-alike

goldfarb.ucf-cs@rand-relay.arpa (04/13/83)

Could someone please post some basic information about the National
Semiconductor CMOS Z80 look-alike.  I'm interested in the extent of
compatibility with the Intel 8085 as well as the extent of instruction
set compatibility with the Z80.  Thanks.
					Ben Goldfarb
					ARPA: goldfarb.ucf-cs@Rand-Relay
					uucp: duke!ucf-cs!goldfarb

pgf (04/19/83)

The NS Z80 look-alike is the NSC800 -  It is essentially a Z80 in 
8085 clothing.  The differences which come immediately to mind (there 
are probably more) are: 1) 8085 has no refresh control, the NSC800 
does on pin 28.  2) the Z80 instruction set has no means of controlling
the serial lines or the maskable interrupts on the 8085 hardware (no 
RIM and SIM instructions), so an internal IO port is used. 3) the NSC800 
has a power-save pin. 
						paul fox ...!houxm!pgf