Fig. 3-5- Page 47

CHAPTER 3  THEORY OF OPERATION

3-5

Fig. 3-5 shows the block diagram of the main PCB of the HL-1250 printer.

Reset Circuit

Program + Font ROM

4.0 Mbytes

RAM

(4.0 Mbytes)

Option RAM (SIMM)

(max. 32Mbytes)

Option Serial I/O

(RS232C & RS422A)

EEPROM (512 x 8 bits)

CPU Core

(MB86832)

A  S  I  C

Oscillator (32.7MHz)

Address Decoder

DRAM Control

Timer

FIFO

CDCC Parallel I/O

Soft Support

EEPROM I/O

Engine Control  I/O

To Engine PCB

BUS

INT

To PC

USB I/O

To PC

Fig. 3-5

HL-1250