APPENDIX
D:
Specifications
The Radio Shack TRS-80 15-Meg Built-in Hard Disk System
is
a •
disk-based computer system with two major parts:
• A display console with a Built-in Hard Disk System and a
built-in double-sided, double-density floppy disk drive.
• A detached keyboard which can be positioned for your
comfort and efficiency
The operating system software
is
loaded from a system diskette
in
Drive
ill
or Drive 4
by
a built-in ROM "bootstrap" program.
Processors
Input/Output Processor System
• Z80-A based with 64K bytes of random
access
memory
• Independent bus can support all the standard system boards
• Emulation mode lets you execute programs previously
developed for the TRS-80 Model
II
without changing them first.
Computational Processor System
• 68000 based with either 128K or 256K (384K or 512K bytes
on
a Model 168) of RAM
• Independent bus can support multiple bus masters
The two processors share the computing load from the application •
programs (the
Z80-A based processor performs input/output tasks
while the
68000 based processor performs computational tasks),
Video Display
LSI Controller Chip
Frees the input/output (Z80-A based) processor from
much
of the
overhead required to update and maintain the video display.
Four Modes
• Green/White on black (normal)
• Black
on
green/white (reversed)
•
80
characters by
24
lines
• 40 characters by 24 lines
Displayable Characters
• Full ASCII set
• 32
graphics
characters
•
60