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Service Guide ML520/521
Chapter 2 Principles of Operation
Program ROM
Location 05CA: 27C1024
This 64k x 16 bit (1Mbit) EPROM contains the control program for the printer. The MPU executes the
instructions contained in this program.
The Program ROM is assigned to the program memory area of the MPU and instructions are fetched by
the PSEN signal of the MPU.
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