Vazeny pane inzenyre,

zasilam Vam slibene priklady jako doplnky k Architekture PC.
Jsou psany pro Turbo Assembler, nevyuzivaji zadne speciality novych verzi, atd.
Je k nim dodan kratky DEMO program pro jejich vyuziti v PASCALU.
Tykaji se:

- obsluhy LED na klavesnici PC
- prevodu HEX-DEC
- prace se stavovymi promennymi klavesnice v BIOSu 

Jsou to jenom malickosti, ale treba nekomu pomohou...

Tomas Pitner
tomp@informatics.muni.cz


PRIKL.ASM
;
; Priklady prace s promennymi BIOSu, s klavesnici,...
; V prostredi Borland Pascalu mozno prekladat pomoci Tools, Turbo Assembler
; nebo primo:
; TASM <volby> <nazev souboru>

        .MODEL MEDIUM, PASCAL   ; pro linkovani s Pascalem

        LOCALS                  ; pouziva lokalni navesti - @@
        .CODE                   ; zacatek kodoveho segmentu

;-----------------------------------------------------------------------------
; Prevod 16 bitoveho slova na retezec HEXA cifer
; Deklarace v Pascalu: HEX2ASC ( Cislo: word, var Retezec: string );
;-----------------------------------------------------------------------------
HEX2ASC PROC    FAR Source: WORD, Dest: DWORD
        USES    AX,BX,CX,DX,DS
        PUBLIC  HEX2ASC

        mov     cx,Source
        mov     dx,cx
        ror     dx,4
        and     cx,0F0Fh
        and     dx,0F0Fh

        add     cx,'00'
        add     dx,'00'
        mov     ah,'9'
        mov     al,'A'-'0'-10

        cmp     dh,ah
        jb      @1
        add     dh,al

@1:     cmp     dl,ah
        jb      @2
        add     dl,al

@2:     cmp     ch,ah
        jb      @3
        add     ch,al

@3:     cmp     cl,ah
        jb      @4
        add     cl,al

@4:
        lds     BX,Dest
        mov     byte ptr [bx],4
        mov     [bx+1],dh
        mov     [bx+2],ch
        mov     [bx+3],dl
        mov     [bx+4],cl
        ret
HEX2ASC ENDP

;-----------------------------------------------------------------------------
; Prevede momentalni stav kontrolniho slova klavesnice v BIOSu na retezec
; ve formatu Pascalu, tj.:
; 0. byte delka
; 1.- delka. byte - vlastni retezec
; Deklarace: FLG2ASC ( var Cil: string );

; mala pismena = 0, velka pismena = 1
; RS - Right Shift                LC - Left Control
; LS - Left Shift                 LA - Left Alt
; CT - Control                    RQ - System Request
; AL - Alt                        PA - Pause
; SS - Stav Scroll Locku          PS - Pressed Scroll Lock
; SN - Stav Num Locku             PN - Pressed Num Lock
; SC - Stav Caps Locku            PC - Pressed Caps Lock
; SI - Stav Insert/Overwrite      PI - Pressed Insert
;-----------------------------------------------------------------------------
FLG2ASC PROC    FAR     Dest: DWORD
        PUBLIC  FLG2ASC

        push    ds
        xor     ax,ax
        mov     ds,ax
        ASSUME  DS:BIOS
        mov     dx,word ptr ds:[417h]
        pop     ds

        ASSUME  DS:@DATA
        les     di, Dest
        mov     al, 48
        stosb
        mov     si, offset KEY

        mov     cx,16
@@0:    lodsw
        ror     dx,1
        jc      @@1
        add     ax,2020h
@@1:    xchg    al,ah
        stosw
        mov     al,' '
        stosb
        loop    @@0
        ret

FLG2ASC ENDP

        .DATA

KEY     DW   'RS','LS','CT','AL','SS','SN','SC','SI'
        DW   'LC','LA','RQ','PA','PS','PN','PC','PI'

;-----------------------------------------------------------------------------
; Priklad obsluhy LED indikatoru na klavesnici

; 1. Zapamatuje si stav LED
; 2. Vytvori "svetelneho hada"
; 3. Po stisku SHIFT, ALT nebo CTRL obnovi puv. stav LED a skonci

; Volani: LED_CNT
;-----------------------------------------------------------------------------
Keybrd  equ 60h

        .CODE

OldLock DW  ?

LED_CNT PROC FAR
        PUBLIC   LED_CNT
        USES     DS

        xor     ax,ax
        mov     ds,ax
        ASSUME  DS:BIOS,CS:@CODE

        mov     dx,[BIOS:417h]
        mov     OldLock,dx

        hlt
@@0:    mov     bl,1
        mov     cx,3

@@1:    mov     al,0EDh
        out     Keybrd,al
        hlt
        mov     al,bl
        out     Keybrd,al
        rol     bl,1
        hlt
        hlt
        hlt
        hlt
        hlt
        hlt
        hlt
        hlt
        hlt
        test    byte ptr [BIOS:417h],0Fh
        jne     Hotovo
        loop    @@1
        jmp     @@0

Hotovo:
        mov     dx,OldLock
        mov     [BIOS:417h],dx
        mov     al,0EDh
        out     Keybrd,al
        hlt
        mov     al,dl
        ror     al,4
        and     al,7
        out     Keybrd,al
        ret
LED_CNT ENDP

BIOS    SEGMENT AT 0

BIOS    ENDS
        END

PRIKL.PAS
{ Zdrojovy text kratkeho DEMA v Pascalu }
program Priklady;
uses crt;

procedure HEX2ASC ( W: WORD; VAR S: STRING ); far; external;
procedure FLG2ASC ( VAR S : STRING ); far; external;
procedure LED_CNT; far; external;

{$L PRIKL}

VAR S: STRING;
    c: char;
begin
repeat
clrscr;
writeln ('Demo pouziti assemblerovskych rutin v Pascalu');
writeln ('<P>riznaky klavesnice, <L>ED na klavesnici, <H>EX to ASCII string, <K>onec');
c:=UpCase(readkey);
case c of
  'P': begin
    writeln('Pro ukonceni stiskni klavesu');
    repeat
      flg2asc(s);
      gotoxy(15,10);
      write(s);
    until keypressed;
    end;

  'L': begin
    writeln('Pro ukonceni stiskni SHIFT, ALT nebo CTRL');
    LED_CNT;
    end;

  'H': begin
    clrscr;
    HEX2ASC ( $ABCD, S );
    writeln ( 'Priklad: $ABCD se prevede na: ',S );
    writeln('Pro ukonceni stiskni klavesu');
    c:=readkey;
    end;
end;
until c='K';
end.