IBM 5100 - Page 162

Chapter 8. Tape and Printer Input and Output
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Input and output involving the tape or printer can be done with an APL shared
variable, which is a specific variable shared between the active workspace and the
tape or printer. During output operations, the data assigned to the shared variable
is printed, or is written on tape. During input operations, data is read from tape
and assigned to the shared variable; the shared variable can then be used in an ex-
pression in the active workspace. To do tape or printer input or output, the
following steps must be performed:
1. Establish a variable to be shared.
2. Open a data file on tape or specify printer output.
3. Transfer the data.
4. Close the data file or terminate the printer output.
5. Retract the variable being shared.
ESTABLISHING A VARIABLE TO BE SHARED
The OSVO function is used to establish the variable name(s) to be shared. The
OSVO function is dyadic (requires two arguments) and is entered as follows:
The left argument must be a 1.
The right argument NAME(S) can be up to eight variables to be shared. If more
than one name is required, the names must be entered as a character matrix with
each row representing a name. For example:
SHARE~3 3p'ONETWOTHR'
SHAI~E
ONE}
Tl,J()" Each row represents a separate variable name.
THR