Category : Files from Magazines
Archive   : PROFILE.ZIP
Filename : TRANSFER.C

#include "stdio.h"
#include "conio.h"
#include "dos.h"
#include "process.h"
#include "malloc.h"
#include "io.h"

void main(int,char *[]);
void print_byte(char);
void draw_point(int,int,int);
void set_mode(int);

void main ( argc , argv )

int argc;
char *argv[];
{
FILE *handle;
long filesize;
char *buffer , *ptr;
unsigned idx , line_num , pixel;
unsigned char first_byte , second_byte;
unsigned char mask , color , first_bit , second_bit;

/* MAKE SURE A FILE NAME WAS SPECIFIED ON THE COMMAND LINE. */

if (argc < 2)
{
printf("\nMust specify name of file to be printed.");
exit(1);
}

/* OPEN THE FILE. */

if ((handle = fopen(argv[1],"rb")) == NULL)
{
printf("\nCannot open %s.",argv[1]);
exit(1);
}

/* DETERMINE THE FILE SIZE, AND ALLOCATE A BUFFER TO HOLD IT. */

filesize = filelength(fileno(handle));
if ((filesize > 65535L) || ((buffer = malloc((unsigned)filesize)) == NULL))
{
printf("\nInsufficient memory.");
fclose(handle);
exit(1);
}

/* READ THE FILE INTO THE BUFFER. */

if (fread(buffer,sizeof(char),(unsigned)filesize,handle) != (unsigned)filesize)
{
printf("\nError reading %s.",argv[1]);
fclose(handle);
exit(1);
}

/* CLOSE THE FILE. */

fclose(handle);

/* PRINT THE FIRST THREE BYTES OF THE FILE,
WHICH SET THE LINE SPACING ON THE PRINTER. */

for (idx = 0 , ptr = buffer; idx < 3; idx++ , ptr++)
print_byte(*ptr);

/* SET THE VIDEO MODE. */

set_mode(4);

/* THE IMAGE IS DIVIDED INTO 25 LINES, EACH OF WHICH IS EIGHT PIXELS HIGH.
GO THROUGH ALL 25, PRINTING AND DISPLAYING. */

for (line_num = 0; line_num < 25; line_num++)
{

/* THE FIRST THING ON EACH LINE IS A FOUR-BYTE CONTROL SEQUENCE,
WHICH SETS UP THE PROPER GRAPHICS MODE ON THE PRINTER. */

for (idx = 0; idx < 4; idx++ , ptr++)
print_byte(*ptr);

/* THE NEXT 640 BYTES OF THE LINE CONSISTS OF 320 PAIRS OF BYTES.
BY LOOKING AT A PARTICULAR BIT FROM THE FIRST BYTE, AND THE
CORRESPONDING BIT FROM THE SECOND BYTE, YOU CAN TELL WHAT
COLOR THE PIXEL ON THE SCREEN SHOULD BE. */

for (idx = 0; idx < 320; idx++ , ptr += 2)
{
print_byte(first_byte = *ptr);
print_byte(second_byte = *(ptr+1));

for (pixel = 0 , mask = 0x80; pixel < 8; pixel++ , mask >>= 1)
{
first_bit = (first_byte & mask) >> (7-pixel);
second_bit = (second_byte & mask) >> (7-pixel);
color = (first_bit << 1) | second_bit;
draw_point(idx,line_num*8+pixel,color);
}
} /* END OF FOR (IDX) */

/* THE LAST THING ON EACH LINE IS A CARRIAGE RETURN AND LINE FEED. */

for (idx = 0; idx < 2; idx++ , ptr++)
print_byte(*ptr);
} /* END OF FOR (LINE_NUM) */

/* NOW PRINT THE LAST THREE BYTES OF THE FILE,
WHICH RESET THE LINE SPACING ON THE PRINTER. */

for (idx = 0; idx < 3; idx++ , ptr++)
print_byte(*ptr);

/* FREE THE BUFFER. */

free(buffer);

/* WAIT FOR A KEYSTROKE, AND THEN EXIT. */

getch();
exit(0);
} /* END OF MAIN */

void print_byte ( ch )

char ch;
{
union REGS regs;

regs.x.dx = 0;
regs.h.ah = 0;
regs.h.al = ch;
int86(0x17,®s,®s);

return;
} /* END OF PRINT_BYTE */


void draw_point( col , row , color)

int col;
int row;
int color;
{
union REGS registers;

registers.x.dx = row;
registers.x.cx = col;
registers.h.al = (unsigned char)color;
registers.h.ah = 0x0C;

int86(0x10,®isters,®isters);
return;
}

void set_mode ( mode )

int mode;
{
union REGS registers;

registers.h.ah = 0;
registers.h.al = (unsigned char)mode;

int86(0x10,®isters,®isters);
return;
}