/* CMOSRAM.C
 *
 *
 *      This example program stores a string (up to 31 bytes) in the
 *      battery-backed CMOS RAM in the real-time clock.
 */

#include <dos.h>

#ifdef __TURBOC__
extern int _Cdecl directvideo = 0;
#endif

void WriteRam(int offset, int dta)
{
	union REGS regs86;

        regs86.h.ah = 0xDD;     /* Micro/sys function */
	regs86.h.al = 0x09;     /* write byte to CMOS RAM */
	regs86.h.bh = offset;
	regs86.h.bl = dta;

	int86(0x1A, &regs86, &regs86);
}

int ReadRam(int offset)
{
	union REGS regs86;

        regs86.h.ah = 0xDD;     /* Micro/sys function */
	regs86.h.al = 0x08;     /* read byte from CMOS RAM */
	regs86.h.bh = offset;

	int86(0x1A, &regs86, &regs86);

	return (regs86.h.al);   /* return data from CMOS RAM */
}

void main(void)
{
	int dta, n;
	char str[80];

	printf("CMOSRAM\n");
	printf("This program displays a string stored in CMOS RAM\n");
	printf("and allows that string to be changed\n");

	for(;;)
	{
		printf("\n\nCurrent string=\"");
		for(n=0;n<31;n++)       /* up to 31 characters */
		{
			dta = ReadRam(n);
			if (!dta)       /* quit if end of string */
				break;
			putch(dta);
		}
		printf("\"\nEnter new string: ");

		gets(str);

		for(n=0; n<31; n++)
		{

			WriteRam(n, str[n]);

			if (!str[n])
				break;
		}
	}
}