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 WAIT portnumber, and-expression% [,xor-expression%]
 
 Usage Notes
   ■ The WAIT statement is an enhanced version of the INP function; it
     suspends execution until a specified bit pattern is input from an input
     port:
     • The data byte read from the port is combined, using an XOR operation,
       with xor-expression%. If xor-expression% is omitted, it is assumed to
       be 0.
     • The result is combined with and-expression% using an AND operation.
     • If the result is zero, the first two steps are repeated.
     • If the result is nonzero, execution continues with the next program
       statement.
 
   ■ It is possible to enter an infinite loop with the WAIT statement if the
     input port fails to develop a nonzero bit pattern. In this case, you
     must manually restart or "cold boot" the machine.
 
   ■ The following program line illustrates the syntax of the WAIT statement:
 
         WAIT  HandShakePort, 2
 
   ■ WAIT causes Visual Basic to do an AND operation on the bit pattern
     received at MS-DOS I/O port HandShakePort with the bit pattern
     represented by 2 (00000010).