pc_parallelget

#PC.ParallelGet

##Syntax PC.ParallelGet (port : int) : nat1

##Description The PC.ParallelGet function is used to read the value of certain pins on a parallel port. The port is specified with the port parameter which can have the value 1, 2 or 3 corresponding to "LPT1", "LPT2" and "LPT3". This procedure can be used to control robots and peripherals.

##Example This program reads and prints the values of the five data pins of the PC's parallel port.

    % Read in the set of pin values from LPT1
    const val : int := PC.ParallelGet (1)   
    put "Pin 10 is: ", (val div 64) mod 2
    put "Pin 11 is: ", (val div 128) mod 2
    put "Pin 12 is: ", (val div 32) mod 2
    put "Pin 13 is: ", (val div 16) mod 2
    put "Pin 15 is: ", (val div 8) mod 2

##Details The five pins that are used for parallel input are pins 10-15. The PC.ParallelGet procedure returns the sum of

64 Pin 10 high 128 Pin 11 high 32 Pin 12 high 16 Pin 13 high 8 Pin 15 high

The mod and div operators can be used to determine which pins are high or low.

##Status Exported qualified.

This means that you can only call the function by calling PC.ParallelGet, not by calling ParallelGet.

##See also pc_parallelput.html procedure.html for a diagram of the pins. That procedure.html is used to set.html the values on the parallel port.