watcom-1

/*
 * Compile and assemble with:
 * wcc -0 -d0 -s -wx -zl -zu main.c
 * wlink FILE main.o FORMAT RAW BIN NAME main.com OPTION NODEFAULTLIBS
 */

#include <stdint.h>

void main(void);
extern void start_main(void);
extern void end_main(void);
#pragma aux _cstart aborts;
/* _cstart does any required initialization and calls main */
void _cstart (void)
{
    #pragma aux start_main = \
        "cld"

    #pragma aux end_main = \
        "cli" \
        "hlt"

    start_main();
    main();
    end_main();
}

void bios_video_int (uint16_t ax, uint16_t bx);
#pragma aux bios_video_int = \
    "int 0x10" \
     parm [ax] [bx] \
     modify exact [];

#define WHITE_ON_BLACK 0x07

void write(uint8_t far *s, uint16_t len)
{
    int i;

    for (i=0; i<len; i++)
        bios_video_int ((0x0e<<8) | s[i], WHITE_ON_BLACK);
}

/* Write a NUL(0) terminated string to the console on page 0 */
void write_str(uint8_t far *s)
{
    while (*s)
        bios_video_int ((0x0e<<8) | *s++, WHITE_ON_BLACK);
}

uint8_t ch = 0;

void main(void)
{
        uint8_t hexchars[] = {'0','1','2','3','4','5','6','7','8','9','A','B',
                                                  'C','D','E','F'};
    char brownfox[] = "The quick brown fox jumps over the lazy dog";

        uint8_t i = 0;
        ch = hexchars[i];
        write (&ch, 1);
    write (&hexchars, sizeof(hexchars));
    write_str (brownfox);
}