Service manual

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REV.-A
Table 2-4 lists the functions of the main components of the C094 MAIN.
Table 2-5. Functions of Main Components of C094 MAIN
IC or Circuit
Functions
TMP90C041F (2C1)
Receives data from the host computer and loads it to the input buffer in RAM.
Expands the input data held in the buffer to create image data. Loads the image
data to the image buffer in RAM. Transfers the image data to the printhead
drive circuit. Also controls various printer mechanism parts, such as the
motors.
E05A66YA (IC4)
This gate array mainly performs the following five functions:
“ Memory management
● Centronics l/F control
● Control panel control
● E2PROM control
● Printhead drive circuit control
PROM
(IC3)
The PROM contains the program that runs the CPU.
RAM
(IC2) The RAM contains the CPU working area and the buffers.
E2PROM (5CI)
The EZPROM is used to store information such as the top-of-form position.
UPA1475H (lCl) Drive circuit for PF motor
SLA7024M (IC5) Drive circuit for CR motor
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