Radio Shack TRS-80 III - Page 12

Z-80
4K or 14K ROM
4K, 16K, 32K, or 48K RAM
REAL TIME CLOCK
UPPER/LOWER CASE
VIDEO
500/1500 BAUD CASSETTE INT.
KEYBOARD INTERFACE
LINE PRINTER INTERFACE
I/O BUS INTERFACE
POWER
SUPPLY
(optional)
POWER
SWITCH
POWER
SUPPLY
BRIGHTNESS
AND
CONTRAST
I/O BUS
LINE
PRINTER
PORT
RS-232
I/O
DISK #1
(optional)
TO
EXTERNAL
DISKS
FLOPPY
DISK
CONTROLLER
(optional)
DISK #0
(optional)
~
FIGURE 1. TRS-80 MODEL III BLOCK DIAGRAM