System information

4.2.7 The M (Move) Command
The M command allows block movement of program or data areas from one location to another
in memory. The M command takes the form:
Ms,f,d
where s is the start address of the move, f is the final address, and d is the destination address.
Data is first removed from s to d, and both addresses are incremented. If s exceeds f, the move
operation stops; otherwise, the move operation is repeated.
4.2.8 The R (Read) Command
The R command is used in conjunction with the I command to read COM and HEX files from
the disk into the transient program area in preparation for the debug run. The R command takes
the forms:
R
Rb
where b is an optional bias address that is added to each program or data address as It is loaded.
The load operation must not overwrite any of the system parameters from 000H through 0FFH
(that is, the first page of memory). If b is omitted, then b = 0000 is assumed. The R command
requires a previous I command, specifying the name of a HEX or COM file. The load address
for each record is obtained from each individual HEX record, while an assumed load address of
100H is used for COM files. Note that any number of R commands can be issued following the I
command to reread the program under test, assuming the tested program does not destroy the
default area at 5CH. Any file specified with the filetype COM is assumed to contain machine
code in pure binary form (created with the LOAD or SAVE command), and all others are
assumed to contain machine code in Intel hex format (produced, for example, with the ASM
command).
Recall that the command,
DDT filename.typ
which initiates the DDT program, equals to the following commands:
DDT
- Ifilename.typ
- R
4.2 DDT Commands CP/M Operating System Manual
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