Debug Ü
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Starts the Debug program, which you can use to test and debug executable
files.
Syntax: DEBUG [[[d:]path]file]
d:path\file
The name of a debugger script file. The debugger should allow
the user to specify a file name to load by the script file.
Debug commands
A Assembles the instructions at a particular address
C Compares two memory ranges
D Displays the contents of the memory
E Enters new or modifies old memory contents
F Fills a range in memory
G Executes a program in memory
H Adds and subtracts two hex values
I Inputs and displays a byte from a port
L Loads disk data into memory
M Copies a range of memory values
N Names a file to load or create
O Outputs a byte to a port
P Proceeds with execution to the next memory instruction
Q Quits Debug
R Displays (and changes) contents of registers and flags
S Searches for characters
T Traces execution of memory code
U Unassembles hex bytes into assembler instructions
W Writes memory data to disk
XA Allocates expanded memory
XD De-allocaes expanded memory
XM Maps logical pages onto physical ones
XS Displays expanded memory status
Example:
This program will read any keystroke and make it easy for you to test
whether or not that key was typed during a batch file's execution:
Create the file keyscan.scr
A 100
MOV AH,0
INT 16
MOV AL,AH
MOV AH,4C
INT 21
RCX
A
N KEYSCAN.COM
W
Q
Then type at the command prompt:
C:\>debug < keyscan.scr