Block Diagram (Main Logic Board) - Star Micronics LC-1011C Technical Manual

1.

Block Diagram (Main Logic Board)

The block diagram of this printer is shown in Fig. 2-1.
(1) Main Logic Board
This board receives data from the host computer and stores it in the RAM in the order it arrives. The CPU on this
board reads the data from the RAM, and edits it according to the program stored in the ROM.
When editing is completed, various drive signals from the CPU are sent to the printer mechanism to perform
printing.
Explanation
• CPU MA3000SOFP
Controls this printer.
• EPROM 1M bit
Contains both the printer control and the character font.
• EE-PROM KM93C46 64 16 bits
Contains the data (EDS data and so on) in the memory switch.
• RAM 64K bit
Used as a stack area, work area and data buffer of the CPU.
• Parallel interface
• Gate array (custom IC)
Inputs/outputs several signals.
• Driver
The data edited by the CPU and gate array are sent to the printer mechanism after conversion to the signal for
the print head drive and motor drives.
(2) Control panel board
Panel circuit for manual control of the printer.
(3) Printer Mechanism
Consists of a print head, carriage motor, paper feed motor, and detectors.
(4) Power Supply Unit
Converts AC power to 25 ~ 45VDC and 5VDC.
Data (From Host Computer)
Parallel
interface
LED
Switch
Masked ROM
Control
1M
panel board
EE-PROM
Power
supply unit
Main logic board
AC Power
Fig. 2-1 Block Diagram
Driver
Gate array
CPU
Driver
RAM
– 19 –
THEORY OF OPERATION
Print head
Carriage
motor
Detectors
Paper feed
motor
Printer
mechanism