Commodore CBM - CMD

If vou forget ta close a file prior ta the program end, vou may ruin your file.
When a file is opened for write, the data is stored in a buffer area prior ta being
transferred ta the tape. If the file
is not closed, the data will probably NOT be
trans1'erred ta the tape. If the data is transferred under these conditions, other
problems can result. If the file is written over a previously recorded tape, and the
file
is not closed, no end-of-file marker is written. This problem will not present it-
self until the file is subsequently read, when either a READ ERROR will be gener-
ated or the tape will be read past where the end-of-file should be, and the remain-
ing
"garbage" on the tape will be read.
CLOSE may be executed in either immediate or program mode. After writing
ta a file, if no tape control key is depressed when a CLOSE is issued, the PET dis-
plays the
following message:
PRESS PLAY & RECORD ON TAPE #l-Press keys
OK • Tape begins moving ta write tape buffer.
No tape control keys need ta
be down for a CLOSE after a READ commando
Examples:
CMD
CLOSE 1
CLOSE 14
A=14
CLOSE A
Close logical file
1.
Close logical file 14.
Same
as above.
The CMD statement directs the PET-user screen dialogue ta another output
device.
Format:
CMD file
where:
file
is the logical file number that was given
when the file was opened.
After a CMD statement output for subsequent PRINT and LIST commands
is directed ta the" commanded" device rather than ta the screen.
CMD may
be executed in immediate or program mode.
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