Part Iv. Theory Of Operation; General - Tandy 102 Service Manual

IV. THEORY OF OPERATION
General
Figure 4-1 shows how this section is organized and highlights significant areas.
Theory of
Operation
General
Block
Diagram
CPU I 1
Memory
Address
Decoding and
Bank Selection
Circuit
Keyboard
System Bus
Cassette
Inte
rf
a ce
Circuit
11
Read Circuit
Remote Circuit
Clock Control
Circuit
Timer Set
Sequence
Timer Read
Sequence
Printer Interface
Circuit
Serial Inte
rf
a ce
Circuit
Bar Code
Reader Interface
Circuit
LCD
fRS-232C/
LCD Common
MODEM
Driver
Selection Circuit
RS-232C LCD Segment
Interface Circuit Driver
MODEM IC LCD Waveform
Transmission
Filter Circuit
Reception Filter
Circuit
MODEM
Transmitting
Level
Adjustment
y
MODEM
Connector
Circuit
Figure 4-1. Organization of Section IV
I
1
I/O Map
Buzzer Control
Circuit
Signal from PB5
of PIO
Using PIO Times
Output
Power Supply
and Auto- Power
ON/OFF Circuit
DC/DC
Converter
Low Power
Detection Circuit
Reset Circuit
4-1