Tandy 102 Service Manual page 5

List of Illustrations
FIGURE
DESCRIPTION
PAGE
NUMBER NUMBER
1-1 Front View ................................................................................................................................ 1-2
1-2 Rear View ................................................................................................................................ 1-3
1-3 Bottom View ............................................................................................................................ 1-4
1-4
Main PCB (Bottom
View)
....................................................................................................... 1-5
1-5 LCD PCB ................................................................................................................................. 1-6
2-1 Top Case Removal ................................................................................................................. 2-1
2-2
Keyboard and LCP PCBs Removal ....................................................................................... 2-1
2-3
Main PCB Removal ................................................................................................................. 2-4
4-1 Organization of Section IV ..................................................................................................... 4-1
4-2 System Block Diagram ........................................................................................................... 4-2
4-3 Functional Block Diagram of Bus Separation Circuit ........................................................... 4-3
4-4
Memory Map ........................................................................................................................... 4-3
4-5
Address Decoding and Bank Selection Circuit .................................................................... 4-4
4-6
I/O Address Decoding Circuit ................................................................................................ 4-5
4-7 Condition of Pressing
"T" Key ............................................................................................... 4-6
4-8
Cassette Interface Circuit ....................................................................................................... 4-7
4-9 Printer Interface Circuit .......................................................................................................... 4-8
4-10
Bar Code Reader Interface Circuit ........................................................................................ 4-9
4-11
Buzzer Control Circuit ............................................................................................................ 4-10
4-12
Time Set Sequence ofuPD1990AC ....................................................................................... 4-12
4-13
Time Read Sequence ofuPD1990AC ................................................................................... 4-13
4-14
Functional Block Diagram of the Serial Interface ................................................................. 4-14
4-15
RS-232C/MODEM Selection Circuit ...................................................................................... 4-15
4-16
RS-232C Interface Circuit ...................................................................................................... 4-16
4-17 MODEM IC and Peripheral Circuit ......................................................................................... 4-17
4-18
Transmission Filter Circuit ..................................................................................................... 4-17
4-19 Reception Filter Circuit ........................................................................................................... 4-18
4-20
MODEM Adjustment ............................................................................................................... 4-19
4-21
MODEM Connector Interface Circuit .................................................................................... 4-20
4-22
HD44103 Internal Logic Diagram .......................................................................................... 4-21
4-23
HD44102 Internal Logic Diagram ..........................................................................................
4-22
4-24
LCD Waveform ........................................................................................................................ 4-23
4-25
Power Supply and Reset Circuit ............................................................................................ 4-25
6-1
Exploded View ........................................................................................................................ 6-1
7-1 Main PCB - Schematic Diagram ............................................................................................
7-1
7-2
LCD PCB - Schematic Diagram ............................................................................................ 7-2
7-3
Main PCB - Top View ............................................................................................................. 7-3
7-4
Main PCB - Bottom View ........................................................................................................ 7-4
7-5
LCD PCB - Top View .............................................................................................................. 7-5
A-1 Installation of RAM and ROM ................................................................................................. A-1
B-1 Keyboard Layout .................................................................................................................... B-1
B-2 System Bus Connector ........................................................................................................... B-2
B-3 RS-232C Connector ............................................................................................................... B-3
B-4 Printer Connector ................................................................................................................... B-4
B-5 Cassette Connector ................................................................................................................ B-5
B-6 MODEM Connector ................................................................................................................ B-5
B-7 Bar Code Reader Connector ................................................................................................. B-6
C-1 Functional Block Diagram ...................................................................................................... C-1
C-2 Pin Configuration of 80C85A ................................................................................................. C-1
C-3 Trap and RESET IN ................................................................................................................. C-5
C-4 80C85A Basic System Timing ............................................................................................... C-7
C-5 Functional Block Diagram ..................................................................................................... C-7
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