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Q62891: WAIT() Causes Execution to Continue If Any Bit Is Set

Article: Q62891
Product(s): See article
Version(s): 4.00 4.00b 4.50
Operating System(s): MS-DOS
Keyword(s): ENDUSER | SR# S900421-2 B_BasicCom | mspl13_basic
Last Modified: 29-JAN-1991

The WAIT() statement stops monitoring the input port and resumes
execution as soon as any bit changes at the input port.

The WAIT() statement cannot be used to suspend program execution until
only a certain bit pattern is read from a designated input port.
However, this can be done using the INP() function as shown in the
program below, which loops until the byte read from port 1 is 13.

This information applies to Microsoft QuickBASIC versions 4.00, 4.00b,
and 4.50, to Microsoft BASIC Compiler versions 6.00 and 6.00b, and to
Microsoft BASIC Professional Development System (PDS) versions 7.00
and 7.10 for MS-DOS.

Code Example
------------

   DO
    x% = INP(1)
   LOOP UNTIL x% = 13

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