CALL tells VISTA to save the contents of its current procedure buffer, read
in the desired procedure file, and begin execution at its first line. The
CALL command can be executed directly in the immediate input mode, or be
used inside procedures to call other procedures. In both cases, at the
completion of the called procedure, VISTA will return properly to either
the input mode or calling procedure. VISTA will support up to 10 levels or
subroutine calls. If an error occurs while a called procedure is
executing, VISTA will unwind and display the complete subroutine stack.
A procedure is allowed a maximum length of 2500 lines, and each line is
allowed a maximum length of 80 characters. If your procedures or lines
exceed this maximum, they will be truncated.
Parameters can optionally be passed to the procedure. These can be numeric
or string parameters. The parameters are evaluated by the procedure using
the PARAMETER command.
Examples: Assume the default procedure directory is /vista/procedure
and the default extension is .pro.