User Memory

Program and data memory for the CPM 790 is provided

by a memory board with 1 Mbyte of battery-backed

CMOS RAM.  512 Kbytes of this memory is available for the

user’s application program and data.  This memory board is

an integral part of the CPM 790 module and is included

with the module.

Flash Memory

This module uses flash memory for storage of the

operating system firmware (this module does not sup

port storage of user program in the flash memory).  This

allows updates of the firmware without disassem

bling the module or replacing EPROMs.  The oper

ating system firmware is updated by connecting a

PC compatible computer to the module’s serial port

and running the Loader software included with the

firmware floppy disk.

Operation, Protection, and Module Status

Operation of this module can be controlled by the

three-position RUN/STOP switch or remotely by an

attached programmer and programming software.

Program and configuration data can be locked

through software passwords or manually by the

memory protect keyswitch.  When the key is in the

protected position, program and configuration data can

only be changed by a programmer connected parallel

only (to the Bus Transmitter module).  The status of a

CPU is indicated by the four green LEDs on the front

of the module.