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/* MOVEMEM.C illustrates direct memory access using functions:
 *      movedata        FP_SEG          FP_OFF
 *
 * Also illustrated:
 *      #pragma pack
 *
 * See COPY2.C, ALARM.C, and SYSCALL.C for more examples of FP_SEG
 * and FP_OFF.
 */
 
#include <memory.h>
#include <stdio.h>
#include <dos.h>
 
#pragma pack( 1 )    /* Use pragma to force packing on byte boundaries. */
 
struct LOWMEMVID
{
    char     vidmode;       /* 0x449 */
    unsigned scrwid;        /* 0x44A */
    unsigned scrlen;        /* 0x44C */
    unsigned scroff;        /* 0x44E */
    struct   LOCATE
    {
        unsigned char col;
        unsigned char row;
    } csrpos[8];            /* 0x450 */
    struct   CURSIZE
    {
        unsigned char end;
        unsigned char start;
    } csrsize;              /* 0x460 */
    char     page;          /* 0x462 */
} vid;
struct LOWMEMVID _far *pvid = &vid;
 
void main()
{
    int page;
 
    /* Move system information into uninitialized structure variable. */
    movedata( 0, 0x449, FP_SEG( pvid ), FP_OFF( pvid ), sizeof( vid ) );
 
    printf( "Move data from low memory 0000:0449 to structure at %Fp\n\n",
             (void _far *)&vid );
 
    printf( "Mode:\t\t\t%u\n", vid.vidmode );
    printf( "Page:\t\t\t%u\n", vid.page );
    printf( "Screen width:\t\t%u\n", vid.scrwid );
    printf( "Screen length:\t\t%u\n", vid.scrlen );
    printf( "Cursor size:\t\tstart: %u\tend: %u\n",
             vid.csrsize.start, vid.csrsize.end );
    printf( "Cursor location:\t" );
    for( page = 0; page < 8; page++ )
        printf( "page:\t%u\tcolumn: %u\trow: %u\n\t\t\t",
                page, vid.csrpos[page].col, vid.csrpos[page].row );
}