CX . ' p . JCXZ , CX . '. ' , , , - , . , . ' , . , JAE JGE , .
3. . CX
. LOOP, , CX. LOOP CX 1. CX , , , CX 0, LOOP . . 7.2, LOOP, 䳿, . 7.1 , . MOV CX 10. LOOP CX, 1 CX DX. JMP A20 LOOP ADD AX,01 INC AX ( AX 1). JMP, LOOP LOOP A20, . LOOP -128 +127 . , "Relative jump out of range" ( ). LOOP , .7.1, , COM-. DEBUG. CX , p AX, BX DX . 000B, 0042 0400. Q. LOOP - LOOPE ( LOOPZ) LOOPNE ( LOOPNZ). CX 1. LOOPE , CX (ZF=1). LOOPNE , CX (ZF=0).
4. .
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ò ֲ: AND, OR, XOR, TEST, NOT
. AND, OR, XOR TEST - . ֳ ASCII (..13). ', CF, OF, PF, SF, ZF.
AND: 1, 1; - 0.
OR: 1, 1; 0, - 0.
XOR: 0, 1, 1; ( - 0 - 1) - 0.
TEST: 䳺 AND- , .
' , . AND,OR XOR :
AND OR XOR
0101 0101 0101
0011 0011 0011
: 0001 0111 0110
' , , AL 1100 0101, BH 0101 1100:
1. AND AL,BH; AL 0100 0100
2. OR BH,AL; BH 1101 1101
3. XOR AL,AL; AL 0000 0000
4. AND AL,00; AL 0000 0000
5. AND AL,0FH; AL 0000 0101
6. OR CL,CL; SF ZF
3 4 . 5 AL. CMP , OR :
1. OR CX,CX; CX
JZ;,
2. OR CX,CX; CX
JS...;,
TEST 䳺 AND, , . :
1. TEST BL,11110000B; BL
JNZ...; ?
2. TEST AL,00000001B; AL
JNZ...; ?
3. TEST DX,OFFH; DX
JZ...; ?
NOT , ': , - . , , p AL 1100 0101, NOT AL 0011 1010. . NOT NEG, - , (." " .1.).
˲
, ', :
- ;
- ';
- ;
- 8 ( ) 16 ( );
- ( ) ( ).
1 c , 1 CL.