SETBIT(OPCSDEFS)	Optical Printer Control System	  SETBIT(OPCSDEFS)

    NAME
        setbit - set bit(s) on a port

    USAGE
        setbit [port] [mask] [softlatch]    # (values hex!)

    EXAMPLES
        setbit 0378 04 0        # lpt1 port bit #2 (1=#0, 2=#1, 4=#2)
        setbit 0306 01 1        # kuper card logic connector,
	                        # bit #1 (note softlatch=1)

    DESCRIPTION
        This command enables bits on port, based on the mask. 
	Basically, the mask is ORed with the port's current value.

	[port] is the port number in hex.

	[mask] is a hex byte value which is OR'ed with the current
	value at the port. (In the case of softlatching, the software latched
	value is OR'ed with the mask, to create the new value that it output
	to the port)

        o With [softlatch] set to 1, only ports 0x0000 - 0x07ff are allowed.
	  Any ports referenced above 0x07ff with [softlatch] enabled will
	  cause an error.

        o External programs that modify a port defined to OPCS as a [softlatch]
	  port (such as would be the case for the kuper logic I/O port) should
	  beware that the OPCS software will be maintaining it's own internal
	  latch for that port, and this latch value will not reflect any 
	  changes that have been made by the external program.
	
	  This is not really a bug, just a fact that cannot be changed. It 
	  is usually bad hardware practice to make WRITE ONLY ports, since 
	  different programs cannot co-communicate with such a port, unless 
	  some common data area is arranged to latch the settings, which can
	  be hard to enforce on PCs.

    BUGS
        o With [softlatch] set to 1, only ports 0x0000 - 0x07ff are allowed.
	  Any ports referenced above 0x07ff with [softlatch] enabled will
	  cause an error.

        o External programs that modify a port defined to OPCS as a [softlatch]
	  port (such as would be the case for the kuper logic I/O port) should
	  beware that the OPCS software will be maintaining it's own internal
	  latch for that port, and this latch value will not reflect any 
	  changes that have been made by the external program.
	
	  This is not really a bug, just a fact that cannot be changed. It 
	  is usually bad hardware practice to make WRITE ONLY ports, since 
	  different programs cannot co-communicate with such a port, unless 
	  some common data area is arranged to latch the settings, which can
	  be hard to enforce on PCs.

    SEE ALSO
        DEENERGIZE(OPCSDEFS)  - define port/bit to deenergize motors
        ALLSTOP(OPDSDEFS)     - define port/bit to detect the allstop key
        BUCKLE(OPCSDEFS)      - define port/bit to detect film buckles
        VIEWER(OPCSDEFS)      - define port/bit to detect viewer open
        TRIPSWITCH(OPCSDEFS)  - define port/bit to detect trip switches
        SETBIT(OPCSDEFS)      - set bit(s) on a port
        CLRBIT(OPCSDEFS)      - clear bit(s) on a port
        XORBIT(OPCSDEFS)      - invert bit(s) on a port

    ORIGIN
	Version K1.12d+ Gregory Ercolano, Venice California 03/04/98