2.OPERATION DESCRIPTION
2.1Element Description
(1)80C51 with MASK ROM
An
(b.) Message buffer.
(c.) Transmission of parallel data to the printer.
(2)SN75189
An
(3)SN75188
An
(4)2764
An 8 kbyte ROM that contains the serial interface control program.
(5)HM6264
An
2.2Circuit Description
A block diagram is shown in Figure
C – 2