//
// THRTEST.C - (DCC-MB) Show throttle values. Requires DCC-MB.COM to be installed.
//

#include <stdio.h>
#include <dos.h>

short DCCQueryDriver(short *, short *);
short DCCReadThrottles(THROTTLE *);

// This structure holds both switch and pot values for a throttle
typedef struct {
    char            bSwitch;
    unsigned char   cPot;
} THROTTLE;

THROTTLE Th[4];

main()
{
    short   i, nDriverMode, nLocos;

    if (DCCQueryDriver(&nDriverMode, &nLocos) != 0xFACE) {
      printf("\007Error: DCC-MB Driver is not installed.");
      return 1;
    }
    printf("\nReading throttle values, hit any key to exit.\n");
    do {
      DCCReadThrottles(Th);
      printf("\r");
      for (i=0; i<=3; ++i) printf ("%3d  %1d     ", Th[i].cPot, Th[i].bSwitch);
    } while (!kbhit());

    return 0;
}

//---------------------------------------------------------------------------
//                      DCC-MB Driver Calls
//---------------------------------------------------------------------------

union _REGS regs;    // structure that holds values of all registers

//::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
short DCCQueryDriver(short *nDriverMode, short *nActiveLocos)
{
    regs.x.ax = 0x00FF;			// "Query" function
    _int86(0x70, &regs, &regs);		// Call the software driver
    *nDriverMode = regs.x.bx;
    *nActiveLocos = regs.x.cx;
    return regs.x.ax;
}
//::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
short DCCReadThrottles(THROTTLE *ThArray)
{
    regs.h.ah = 202;			// "Read Throttles" function
    _int86(0x70, &regs, &regs);		// Call the software driver
    ThArray[0].cPot = regs.h.ch;
    ThArray[0].bSwitch = regs.h.al & 1;
    ThArray[1].cPot = regs.h.cl;
    ThArray[1].bSwitch = (regs.h.al & 2) >> 1;
    ThArray[2].cPot = regs.h.dh;
    ThArray[2].bSwitch = (regs.h.al & 4) >> 2;
    ThArray[3].cPot = regs.h.dl;
    ThArray[3].bSwitch = (regs.h.al & 8) >> 3;
    return regs.x.ax;
}
//::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::