Z80 microprocessor

One of the three operating modes of the Commodore 128 is the CP/M mode, utilizing a Z80 microprocessor. Commodore owners have generally not paid much attention to CP/M, and though it has been available for the 64 for some time now, many people still don t know what it is or what it does. 

Most CP/M programs are written in 8080 or Z80 machine language. CP/M takes care of the minor differences between Z80 machines, but you still have to have a Z80 microprocessor. CP/M could be translated to run on any computer, such as the 6502, but what good is a 6502 version of CP/M if all the programs that run under CP/M are written in Z80 machine language ... 

In electrothermal atomization methods, the microcomputer also controls the furnace temperature, a key factor for this technique. Guevremont and Whitman used a microcomputer based on a Z80 microprocessor for the automatic control and data acquisition from a graphite furnace [13] they could heat the furnace from 0 to 2500 C In about 3 s, with an approximate gain In precision of 50% under the control of the microprocessor. The system Is shown schematically In Fig. 10.9. The automatic functions afforded are data acquisition, measurement of the furnace temperature and calibration, temperature programming, control of the gas flow, control of the sampler and delivery of results. 

The computerized system consists of a Cromenco computer with a Z80 microprocessor, 64 kb of memory and access to various peripherals, and different interfaces such as a serial-parallel Cromenco TU-ART interface, 8- and 12-blt A/D and D/A converters and a parallel-reading I/O Cromenco 4 PIO unit. 

Both of the above data collection systems contain Z80 microprocessor control units, slaved from the system computer, to control movement of the nozzle scanner. 

The MMU also controls the fast serial port used with the 1571 disk drive (and conceivably with other fast peripherals). It determines the clock speed of the 8502, and controls which of the three microprocessors (6510, 8502, Z80) is in control. And although not supported in ROM, it s possible to have all three microprocessors running by quickly switching between them. 

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