i86/mtx/mtx/samples/LAB5.timer/USER/u2.s

   1 .globl begtext, begdata, begbss                      ! needed by linker
   2 .globl _getc,_putc,_getcs
   3 .globl _main, _syscall
   4
   5 .text                                                ! these tell as:
   6 begtext:                                             ! text,data,bss segments
   7 .data                                                ! are all the same.
   8 begdata:
   9 .bss
  10 begbss:
  11 .text
  12
  13         call _main
  14
  15 dead:   jmp   dead
  16
  17 _getcs:
  18         mov   ax, cs
  19         ret
  20
  21         !---------------------------------------------
  22         !  char getc[]   function: returns a char
  23         !---------------------------------------------
  24 _getc:
  25         xorb   ah,ah           ! clear ah
  26         int    0x16            ! call BIOS to get a char in AX
  27         ret
  28
  29         !----------------------------------------------
  30         ! void putc[char c]  function: print a char
  31         !----------------------------------------------
  32 _putc:
  33         push   bp
  34         mov    bp,sp
  35
  36         movb   al,4[bp]        ! get the char into aL
  37         movb   ah,#14          ! aH = 14
  38         mov    bx,#0x000E           ! bL = display page#
  39         int    0x10            ! call BIOS to display the char
  40
  41         pop    bp
  42         ret
  43
  44 _syscall:
  45         int    80
  46         ret
  47