CBM-920 User’s Manual

5.3Explanation of Input/Output Signals

1) Input Signals into Printer

 

DATA 1

8 bit parallel signal (positive logic)

 

DATA 2

8 bit parallel signal (positive logic)

 

DATA 3

8 bit parallel signal (positive logic)

 

DATA 4

8 bit parallel signal (positive logic)

 

DATA 5

8 bit parallel signal (positive logic)

 

DATA 6

8 bit parallel signal (positive logic)

 

DATA 7

8 bit parallel signal (positive logic)

 

DATA 8

8 bit parallel signal (positive logic)

 

 

 

Strobe signal to read 8 bit data (negative logic)

 

STB

 

 

 

 

 

RESET

Signal to reset the whole printer (negative logic)

 

 

 

 

4 ms or more

2) Output Signals from Printer

 

 

8 bit data request signal (negative logic)

 

ACK

........................

 

BUSY

Signal to show BUSY state. Input new data at "LOW" (positive logic)

 

PE

Signal to indicate shortage of paper (positive logic)

 

 

 

Signal to indicate occurrence of trouble, such as mechanical al arm (positive logic)

 

FAULT

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CITIZEN

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Citizen Systems CBM-920 manual Explanation of Input/Output Signals, ACK Busy