Display Refresh Memory; Specifications - Facit 4431 Service Instruction

42
TABLE OF CONTENTS
1
1. 1
1.2
2
2. 1
2.2
3
3. 1
3.2
3.3
3.4
3.5
3.5.1
3. 5. 1. 1
3.5.1.2
3.5.2
3.5.2.1
3.5.2.2
3.5.2.3
3.5.2.4
4
4. 1
4.2
4.3
4.4
5
5. 1
5.2
6
6. 1
6.2
6.3
6.4
6.5
6.6
7
7. 1
7. 1 . 1
7
.1.2
7
.1.3
7. 1. 4
7. 1. 5
7.2
7.2.1
7.2.2
7.2.3
7.2.4
7.3
7. 3. 1
7.3.2
7.3.3
I NT R 0 DU CT I 0 N _ _ _ _ _ _ _ _ _ _ _ _ _ _ 2
DESIGN
SPECIFICATIONS
R E C E I V
1
N G , U N P A C K I N G A N D
I N S P E C T I 0 N _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 3
POWER AND SIGNAL WIRING
I
POWER ON/PERFORMANCE CHECK
INSTALLATION 4
INITIAL SETTING-UP
I
ACCESS TO MAIN LOGIC BOARD IN DISPLAY UNIT 5
ACCESS TO KEYBOARD PCB
I
KEYCLICK/BELL VOLUME ADJUSTMENT
JUMPERS ON THE MAIN LOGIC BOARD 6
KEYBOARD PCB
Facit 4431 Selection (W2)
National Keyboard Selection (W4,5,6)
MAIN LOGIC BOARD
+5V on I/O Connector Pin 18 (W1)
Standard/Extended Character Generator (W3) _ _ _ _ _ _ _ 7
Production Test (W4)
I
Disable/Enable Save (W5)
I N T E R F A C E I N F
0
R M A T I
0
N 8
V.24/RS-232-C COMMUNICATION INTERFACE
V.24/RS-232-C PRINTER INTERFACE
CURRENT LOOP INTERFACE
COMPOSITE VIDEO OUTPUT
S E T - U P F E A T U R E S
GENERAL FEATURES OF SET-UP MODE
SET -UP MODE SUMMARY _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
9
G E N E R A L B L
0
c
K D I A G R A M
I
D E S C R I P T I 0 N 10
MICRO-PROCESSOR CONTROL UNIT
I
DISPLAY REFRESH MEMORY 11
SYNCHRONIZATION GENERATOR
I
VIDEO GENERATOR
INPUT/OUTPUT INTERFACE 13
KEYBOARD SYSTEM
I
D E T A I L E D F U N C T I 0 N A L
D E S C R I P T I 0 N
14
MICRO-PROCESSOR CONTROL UNIT
I
CPU CLOCK
POWER ON RESET
PROGRAM MEMORY ACCESS 15
SCREEN ATTRIBUTE LATCH
EAR OM
DISPLAY REFRESH MEMORY
WAIT STATE GENERATION
WRITING TO THE ASCII (Character) DISPLAY MEMORY _ _ _ _ _ 16
READING THE ASCII ·(Character) DISPLAY MEMORY
WRITING/READING THE ATTR (Attribute) DISPLAY RAM
SYNCRONIZATION GENERATOR
CRT CONTROLLER (CRTC)
DOT OSCILLATOR _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 17
MEMORY SHARE SIGNAL 17-18