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I/O Handling
167
Because of the possibility that a RESET (
IC@ll@ffi),
or similar interruption, may occur between
the first and second calls to the utility, it is recommended that the first call have a definite valid
value for the select code in A (as above). In that way, should there indeed be an interruption, a
valid select code for the printer can be assured.
Utility:
Print_string
General Procedure:
The utility is given the address of a string, and it prints that string to the
standard system printer.
Special Requirements:
The string to be printed must be in standard string format (see "Data
Structures" in Chapter 3). The string must be no longer than 506 characters.
Calling Procedure:
1. Load register A with the address of the string to be printed.
2. Call the utility.
Exit Conditions:
RET 1 If a memory overflow occurs during execution of the utility.
RET 2
If the
@ffi
key is pressed during execution of the utility.
RET 3
If all goes normally.
For example -
":'T'
'!
_.. 1
~
i
i-
:"'·F":·
" ! : l!'
'1:::'::::.:-
~-.""
CAUTION
Pressing RESET
(lcoNnll
STOP
I)
during execution of the
Print string utility may cause a SCRATCH A to occur.
-
I
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