System information

Following the sign-on message, DDT prompts you with the hyphen character, -, and waits for
input commands from the console. You can type any of several singlecharacter commands,
followed by a carriage return to execute the command. Each line of input can be line-edited using
the following standard CP/M controls:
Table 4-1. Line-editing Controls
Control Result
rubout removes the last character typed
CTRL-U removes the entire line, ready for retyping
CTRL-C reboots system
Any command can be up to 32 characters in length. An automatic carriage return is inserted as
character 33, where the first character determines the command type. Table 4-2 describes DDT
commands.
Table 4-2. DDT Commands
Command
Character Result
A enters assembly-language mnemonics with operands.
D displays memory in hexadecimal and ASCII.
F fills memory with constant data.
G begins execution with optional breakpoints.
I sets up a standard input File Control Block.
L lists memory using assembler mnemonics.
M moves a memory segment from source to destination.
R reads a program for subsequent testing.
4-2