ProfitPress Mega CDROM2 …eeware (MSDOS)(1992)(Eng)/ProfitPress-MegaCDROM2.B6I/UTILITY/SYSTEM/JOYREAD.ZIP/JOYREAD.ASM

Assembly Source File | 1989-09-01 | 13.1 KB | 477 lines

;******************************************************************************
;
;  Program:    JOYREAD.ASM
;
;  Purpose:    This code compiles to a .COM program that reads and displays
;           the status of the buttons and potentiometers on the joystick(s)
;           attached to the Game Adaptor port of an IBM-PC compatible computer.
;
;  Usage  :    This program requires MASM (or equivalent), LINK and EXE2BIN
;           to be converted to a .COM program, as follows...
;
;           masm joyread;
;           link joyread;
;           exe2bin joyread joyread.com
;           del joyread.obj
;           del joyread.exe
;
;              The final JOYREAD.COM program may be run from the DOS prompt.
;
;  Programmer: M. B. Young
;
;******************************************************************************
;
;  The Equates Corral
;
      ESCAPE      equ   1Bh
;
      VIDEO       equ   10h
;
         SET_MODE    equ   0
         SET_CRSR    equ   2
         WRITE_TTY   equ   0Eh
         GET_MODE    equ   0Fh
;
      CONFIGURATION  equ   11h
;
      IO_EXTRA    equ   15h
;
         READ_JSTK   equ   84h
;
      KEYBOARD    equ   16h
;
         KBD_READ    equ   0
         KBD_STATUS  equ   1
;
      DOS_CALL    equ   21h
;
         E_C_EXIT    equ   4Ch
;
      GAME_PORT   equ   201h
      MAX_COUNT   equ   100h
;
;******************************************************************************
;
;     Main Code
;
;******************************************************************************
;
joyread_code   segment  para   'code'
;
      assume cs:joyread_code, ds:joyread_code, es:joyread_code
      org 100h
;
begin:
;
      mov ah , GET_MODE             ; save initial video mode
      int VIDEO
      mov old_mode , ax
      mov ah , SET_MODE
      mov al , 3
      int VIDEO                     ; set to 80x25, colour text mode
;
      mov si , offset msg1          ; print title
      mov cx , msg1_len
      mov dh , 1
      mov dl , 22
      call text_print
;
      mov si , offset msg2          ; print column headings
      mov cx , msg2_len
      mov dh , 3
      mov dl , 19
      call text_print
;
      mov si , offset msg3          ; print stick1, status line 1
      mov cx , msg3_len
      mov dh , 5
      mov dl , 19
      call text_print
;
      mov si , offset msg4          ; stick1, status line 2
      mov cx , msg4_len
      mov dh , 6
      mov dl , 19
      call text_print
;
      mov si , offset msg5          ; stick2, status line 1
      mov cx , msg5_len
      mov dh , 9
      mov dl , 19
      call text_print
;
      mov si , offset msg6          ; stick2, status line 2
      mov cx , msg6_len
      mov dh , 10
      mov dl , 19
      call text_print
;
      mov si , offset msg7          ; pot read method
      mov cx , msg7_len
      mov dh , 12
      mov dl , 6
      call text_print
;
      mov si , offset mode2         ; default is BIOS Int 15h, Fn 84h
      mov cx , mode_len
      mov dh , 12
      mov dl , 53
      call text_print
;
      mov si , offset msg8          ; quitting instructions
      mov cx , msg8_len
      mov dh , 16
      mov dl , 30
      call text_print
;
main_event:
;
      call buttons                  ; get and display button states
      call pots                     ; get and display potentiometer values
      mov ah , KBD_STATUS           ; see if user pressed a key
      int KEYBOARD
      jz main_event                 ; no, loop back
      mov ah , KBD_READ             ; yes, see what key was pressed
      int KEYBOARD
      cmp al , ESCAPE
      je get_going
      cmp al , 'm'                  ; does user want to toggle pot read mode ?
      jz toggle_mode
      cmp al , 'M'                  ; just in case...
      jnz main_event
;
toggle_mode:
      mov al , pot_mode             ; get current mode
      xor al , 0FFh                 ; and flip it
      mov pot_mode , al
      mov si , offset mode1         ; display current mode
      or al , al
      jz toggle_1
      mov si , offset mode2
;
toggle_1:
      mov cx , mode_len
      mov dh , 12
      mov dl , 53
      call text_print
      jmp main_event
;
get_going:
      mov ax , old_mode             ; restore initial video mode
      mov ah , SET_MODE
      int VIDEO
;
      xor al , al                   ; set return code = 0
      mov ah , E_C_EXIT
      int DOS_CALL
;
;
;  Sneak in a data segment here
;
;
      msg1        db    '-Joystick Status/Calibration Program-'
      msg1_len    equ   $-msg1
      msg2        db    '              Potentiometers    Buttons'
      msg2_len    equ   $-msg2
      msg3        db    'Stick1-           X:             1:'
      msg3_len    equ   $-msg3
      msg4        db    '                  Y:             2:'
      msg4_len    equ   $-msg4
      msg5        db    'Stick2-           X:             1:'
      msg5_len    equ   $-msg5
      msg6        db    '                  Y:             2:'
      msg6_len    equ   $-msg6
      msg7        db    'Press M to toggle Potentiometer read method:'
      msg7_len    equ   $-msg7
      msg8        db    'Press <Esc> to quit'
      msg8_len    equ   $-msg8
      mode1       db    'Direct Software Loop'
      mode_len    equ   $-mode1
      mode2       db    'BIOS Int 15h, Fn 84h'
;
      string      db    '     '
      is_on       db    'ON '
      is_off      db    'OFF'
      old_mode    dw    ?
      pot_counts  db    4 dup( 0 )
      pot_mode    db    0FFh
;
;
;******************************************************************************
;
;     TEXT_PRINT  -  Prints a message to the screen
;     Assumes that:  ds:[si] -> beginning of string
;                    cx = number of bytes in string
;                    dh,dl = row,col to print string at
;
;******************************************************************************
;
text_print  proc  near
;
      push ax
      push bx
      mov ah , SET_CRSR
      xor bx , bx
      int VIDEO
tp_1:
      lodsb
      mov ah , WRITE_TTY
      int VIDEO
      loop tp_1
;
      pop bx
      pop ax
      ret
;
text_print  endp
;
;
;******************************************************************************
;
;     I_TO_A - converts the value in ax to an ASCII string
;     Assumes that:  es:[di] -> end of a string buffer long enough to hold
;                       the decimal representation of the value in ax
;
;******************************************************************************
;
i_to_a   proc  near
;
      push cx
      push dx
      mov cx , 10
i2a_1:
      xor dx , dx                   ; clear 'high byte'
      div cx                        ; divide ax by 10
      add dl , '0'                  ; convert remainder to ASCII
      mov [di] , dl                 ; store in srrihg buffer
      dec di
      cmp ax , 0                    ; check if quotient > 0
      ja i2a_1
;
      pop dx
      pop cx
      ret
;
i_to_a   endp
;
;
;******************************************************************************
;
;     BUTTONS -  Reads and displays the status of the buttons... the settings
;              are returned in bits 4-7 of al after reading the game adaptor
;              port. A high bit (1) corresponds to an open (unpressed) state.
;
;******************************************************************************
;
buttons  proc  near
;
      mov dx , GAME_PORT            ; read game adaptor port
      in al , dx
      push ax
;
      mov si , offset is_off
      test al , 00010000b           ; Stick 1, Button 1
      jnz br_1
      mov si , offset is_on
br_1:
      mov cx , 3
      mov dh , 5
      mov dl , 55
      call text_print
;
      pop ax
      push ax
      mov si , offset is_off
      test al , 00100000b           ; Stick 1, Button 2
      jnz br_2
      mov si , offset is_on
br_2:
      mov cx , 3
      mov dh , 6
      mov dl , 55
      call text_print
;
      pop ax
      push ax
      mov si , offset is_off
      test al , 01000000b           ; Stick 2, Button 1
      jnz br_3
      mov si , offset is_on
br_3:
      mov cx , 3
      mov dh , 9
      mov dl , 55
      call text_print
;
      pop ax
      mov si , offset is_off
      test al , 10000000b           ; Stick 2, Button 2
      jnz br_4
      mov si , offset is_on
br_4:
      mov cx , 3
      mov dh , 10
      mov dl , 55
      call text_print
;
      ret
;
buttons  endp
;
;
;******************************************************************************
;
;     POTS - reads and displays the potentiometer settings
;
;******************************************************************************
;
pots  proc  near
;
      test pot_mode , 1             ; get current mode
      jnz use_bios
      mov si , offset pot_counts
      call time_pots
      jmp display_counts
;
use_bios:
      mov ah , READ_JSTK
      mov dx , 1
      int IO_EXTRA
      mov si , offset pot_counts
      mov [si] , al
      mov [si+1] , bl
      mov [si+2] , cl
      mov [si+3] , dl
;
display_counts:
      cld
      mov al , ' '                  ; space-out the string
      mov si , offset string
      mov di , si
      mov cx , 4
rep   stosb
      dec di
      xor ah , ah
      mov al , byte ptr pot_counts     ; Stick 1, X-pot
      call i_to_a
      mov cx , 5
      mov dh , 5
      mov dl , 39
      call text_print
;
      mov al , ' '                  ; space-out the string
      mov si , offset string
      mov di , si
      mov cx , 4
rep   stosb
      dec di
      xor ah , ah
      mov al , byte ptr pot_counts + 1 ; Stick 1, Y-pot
      call i_to_a
      mov cx , 5
      mov dh , 6
      mov dl , 39
      call text_print
;
      mov al , ' '                  ; space-out the string
      mov si , offset string
      mov di , si
      mov cx , 4
rep   stosb
      dec di
      xor ah , ah
      mov al , byte ptr pot_counts + 2 ; Stick 2, X-pot
      call i_to_a
      mov cx , 5
      mov dh , 9
      mov dl , 39
      call text_print
;
      mov al , ' '                  ; space-out the string
      mov si , offset string
      mov di , si
      mov cx , 4
rep   stosb
      dec di
      xor ah , ah
      mov al , byte ptr pot_counts + 3 ; Stick 2, Y-pot
      call i_to_a
      mov cx , 5
      mov dh , 10
      mov dl , 39
      call text_print
;
      ret
;
pots  endp
;
;******************************************************************************
;
;     TIME_POTS - Reads the settings of the joystick potentiometers connected
;                 to the game adaptor. Call with ds:[si] pointing to a 4 byte
;                 array to hold the four count values
;
;******************************************************************************
;
time_pots   proc  near
;
      mov dx , GAME_PORT
      cli                           ; disable interrupts during timing loop
      out dx , al                   ; initialize timers
      mov cx , MAX_COUNT            ; maximum wait value
      mov bl , 00001111b            ; use bl to record timer states
;
time_1:
      in al , dx                    ; get timer states  (bits 0-3)
      and al , bl                   ; mask out bits 4-7
      cmp al , bl                   ; has states changed ?
      loopz time_1                  ; no changes
      jcxz time_2                   ; exceeded maximum wait time
      xor al , bl                   ; save changed timer states in al
      mov ah , cl                   ; and count down value in ah
      push ax                       ; save on stack
      dec cx                        ; account for elapsed time
      xor bl , al                   ; update timer states
      jnz time_1                    ; continue if any timers still high
      jmp time_3
;
time_2:
      push bx                       ; timed out
;
time_3:
      sti                           ; all done reading pots, restore interrupts
      mov dl , 4                    ; convert pushed values to counts
;
time_4:
      pop ax                        ; get count-change pair
      sub ah , MAX_COUNT - 1        ; convert count down value to time
      neg ah
      mov cx , 4                    ; now see which pot this pair is for
;
time_5:
      shr al , 1                    ; set CF if low bit is 1
      jnc time_6
      mov [si] , ah                 ; store count value
      dec dl                        ; one timer down, dl yet to do
;
time_6:
      inc si                        ; point to next timer save byte
      loop time_5                   ; test current count-change pair again
      sub si , 4                    ; point si back to start of array
      or dl , dl                    ; have we got readings for all 4 pots ?
      jnz time_4                    ; not yet
;
      ret                           ; all done
;
time_pots   endp
;
;******************************************************************************
;
;     Th-th-th-that's all folks....
;
;******************************************************************************
;
joyread_code   ends
;
               end begin