Radio Shack TRS-80 26-3650

3.
CPU
(Central
Processing
Unit) HD61913
3-1
.
Features
o
CMOS
one-chip CPU
o
Built-in ROM:
100864
bits
o
Built-in RAM: 1896
bits
o
Built-in display
driver
o
Memory
backup
function
o
Clock: 400
kHz
Internal
machine
cycle:
200
kHz
Minimum
instruction
execute time:
10/xS
3-2.
CPU
Block
Diagram
Control signals
A
ROM
(System
Program)
7\
Instruction
Decoder
Address
Control
V
Keyboard Signals
-
4
-