Radio Shack TRS-80 Model II Reference Manual page 53

Model II TRSDOS
DEBUG
Start Debugger
.
DEBUG {switch}
switch is one ofthe following parameters:
ON turns on the debugger.
OFF turns off the debugger.
If switch is omitted and debugger is off,
TRSDOS
tells you so.
If switch is omitted and debugger is on,
TRSDOS
enters the debug monitor.
This command sets up the debug monitor, which allows you to enter, test, and
debug machine-language programs. It also includes an Upload function to
allow transmission of data from another device to the Model II, via the built-
in serial interface (Channel B).
DEBUG
loads into the high memory area sometimes reserved by
TRSDOS
for
special programming (see
TRSDOS
Memory Map). While
DEBUG
is on,
TRSDOS
will automatically protect this area from being overlaid by
BASIC
or
other user programs. To use
DEBUG
from
BASIC,
you must turn
DEBUG
on
before you start
BASIC.
While
DEBUG
is on, every time you attempt to load and execute a user
program, you will enter the debug monitor. In this mode, you can enter any of
a special set of single-key commands for studying how your program is
working.
DEBUG
can only be used on programs in the user area
X'2800'
to
TOP).
Examples
DEI3UG
If
DEBUG
is off, this command tells you so. Hit is on, this command enters the
debug monitor.
DEBUG OFF
Turns off
DEBUG
and l;ln-protects high memory.
DEBUG ON
Turns on
DEBUG:
i.e., loads the debl1gger into high memory, protects high
memory, and sets up a "scroll window" - a block of lines that will be scrolled.
The scroll window will consist of the bottom 11 lines of the display. The top 13
lines will be used to contain the debug monitor display.
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