Category : C Source Code
Archive   : SCANCODE.ZIP
Filename : SCANCODE.C

 
Output of file : SCANCODE.C contained in archive : SCANCODE.ZIP
/* scancode.c -- uses interrupt 22 to read IBM keyboard scancodes */
/* Written by George A. Stanislav, February 17, 1987 for strictly */
/* educational purposes. */

#include
#include /* For MicroSoft C */
#define BIOS_CALL 0x16 /* hexadecimal value of 22 */
#define RIGHT 0x01 /* right shift key mask */
#define LEFT 0x02 /* left shift key mask */
#define CTRL 0X04 /* control key mask */
#define ALT 0x08 /* alt key mask */
#define SCROLL 0x10 /* scroll lock mask */
#define NUMBER 0x20 /* number lock mask */
#define CAPS 0x40 /* caps lock mask */
#define INSERT 0x80 /* insert state mask */

main()
{
unsigned code, shkey;
unsigned scancode(), shift();

printf("Press a key to get its scan code.\nPress to end.\n");
while ((code=scancode()) != 1)
{
printf("\nThe scan code of the key you pressed is %u, or %#x.\n",code,code);
if ((shkey = shift()) != 0)
{
if ((shkey & RIGHT) != 0)
printf("Right shift key is depressed.\n");
if ((shkey & LEFT) != 0)
printf("Left shift key is depressed.\n");
if ((shkey & CTRL) != 0)
printf("Control key is depressed.\n");
if ((shkey & ALT) != 0)
printf("Alt key is depressed.\n");
if ((shkey & SCROLL) != 0)
printf("Scroll state is active.\n");
if ((shkey & NUMBER) != 0)
printf("Number lock is engaged.\n");
if ((shkey & CAPS) != 0)
printf("Caps lock is engaged.\n");
if ((shkey & INSERT) != 0)
printf("Insert state is active.\n");
}
}
printf("\nThe scan code for is %u, or %#x.\n\nBye.",code,code);
}

unsigned scancode()
{
union REGS regin, regout; /* input, output register values */
unsigned code; /* scan code */

regin.h.ah = 0; /* will wait till a key is pressed, read it, */
/* return its scan code and remove it from keyboard */
/* buffer. To read it WITHOUT removing it from the */
/* buffer (so it can be scanf() later), use 1 instead */
int86(BIOS_CALL, ®in, ®out);
code = regout.h.ah; /* the scan code is in the AH register */
return code;
}

unsigned shift()
{
union REGS regin, regout; /* input, output register values */
unsigned shstatus; /* shift status */

regin.h.ah = 2; /* gets the status of all "shift" keys */
int86(BIOS_CALL, ®in, ®out);
shstatus = regout.h.al; /* the status is in the AL register */
return shstatus;
}



  3 Responses to “Category : C Source Code
Archive   : SCANCODE.ZIP
Filename : SCANCODE.C
”

  1. Daniel says:
    January 27, 2013 at 3:59 pm

    Very nice! Thank you for this wonderful archive. I wonder why I found it only now. Long live the BBS file archives!

  2. Joshie says:
    March 18, 2014 at 4:57 pm

    This is so awesome! 😀 I’d be cool if you could download an entire archive of this at once, though.

  3. DiskingRound says:
    January 14, 2015 at 10:57 pm

    But one thing that puzzles me is the “mtswslnkmcjklsdlsbdmMICROSOFT” string. There is an article about it here. It is definitely worth a read: http://www.os2museum.com/wp/mtswslnk/