NAME
        CardProgramVoltage -- Set programming voltage.

   SYNOPSIS
        success=CardProgramVoltage( handle, voltage );
                                        a1      d0

        long cardprogramvoltage( struct cardhandle *, ulong );

   FUNCTION
        Used to set programming voltages (e.g., for FLASH-ROM/EPROM
        cards).

   INPUTS
        handle - Same handle as that used when owncard() was called.

        voltage - See card.i/h for valid values.

   RETURNS
        1  - Successful.

        0  - Not successful.  Most likely because the credit-card
        card has been removed, and you are no longer the owner.

        -1 - This function is not being supported.  On some machines
        with a minimal (hardware) credit-card interface, this feature
        may not be possible.

   NOTES
        This function may be called from within a task, or from a level 1
        or level 2 interrupt.

       !!!WARNING!!!

        Flash-ROM programming requires careful coding to prevent
        leaving the Erase command on too long.  Failure to observe
        the maximum time between the Erase command, and the Erase-Verify
        command can make a Flash-ROM card unusable.  Some Flash-ROM cards
        may provide an internal watch-dog timer which protects the card.

        Because of the relatively long time (e.g., 10ms) between Erase, and
        Erase-Verify which must be observed, the need for such critical
        timing can be problematic on a multi-tasking machine.

        Vendors of Flash-ROM's recommend a high priority interrupt
        generated by a 10ms timer be used to turn off Erase.  On the
        Amiga this can be accomplished by using a CIA-B interval timer.
        The timer.device also provides a mechanism for generating a low
        priority interrupt.  The timer.device is easier to use than cia
        interval timers, though not as accurate or as safe.

        Even if the Flash-ROM card provides an internal watch-dog timer,
        implementation of the code during Erase should assume that
        the Flash-ROM does not.

   SEE ALSO
        owncard(), resources/card.h, resources/card.i