Assembly part 2.

Basic Instructions

; Program to show use of interrupts
; Also, Hello World program !
hello: DB "Hello World" ; store string

; actual entry point of the program, must be present
start:
MOV AH, 0x13            ; move BIOS interrupt number in AH
MOV CX, 11              ; move length of string in cx
MOV BX, 0               ; mov 0 to bx, so we can move it to es
MOV ES, BX              ; move segment start of string to es, 0
MOV BP, OFFSET hello    ; move start offset of string in bp
MOV DL, 0               ; start writing from col 0
int 0x10                ; BIOS interrupt

CMP

CMPX1,X2 JMP

• JE (Jump if Equal): Jumps if the Zero Flag (ZF) is set (ZF = 1).
• JNE (Jump if Not Equal): Jumps if the Zero Flag (ZF) is not set (ZF = 0).
• JZ (Jump if Zero): Jumps if the Zero Flag (ZF) is set (ZF = 1).
• JNZ (Jump if Not Zero): Jumps if the Zero Flag (ZF) is not set (ZF = 0).
• JS (Jump if Sign): Jumps if the Sign Flag (SF) is set (SF = 1).
• JNS (Jump if Not Sign): Jumps if the Sign Flag (SF) is not set (SF = 0).
• JC (Jump if Carry): Jumps if the Carry Flag (CF) is set (CF = 1).
• JNC (Jump if Not Carry): Jumps if the Carry Flag (CF) is not set (CF = 0).
• JO (Jump if Overflow): Jumps if the Overflow Flag (OF) is set (OF = 1).
• JNO (Jump if Not Overflow): Jumps if the Overflow Flag (OF) is not set (OF = 0).
• JA (Jump if Above): Jumps if (CF = 0 and ZF = 0).
• JAE (Jump if Above or Equal): Jumps if (CF = 0).
• JNA (Jump if Not Above): Jumps if (CF = 1 and ZF = 1).
• JNAE (Jump if Not Above or Equal): Jumps if (CF = 1).
• JG (Jump if Greater): Jumps if (ZF = 0 and SF = OF).
• JGE (Jump if Greater or Equal): Jumps if (SF = OF).
• JNG (Jump if Not Greater): Jumps if (ZF = 1 or SF != OF).
• JNGE (Jump if Not Greater or Equal): Jumps if (SF != OF).
• JB (Jump if Below): Jumps if (CF = 1).
• JBE (Jump if Below or Equal): Jumps if (CF = 1 or ZF = 1).
• JNB (Jump if Not Below): Jumps if (CF = 0).
• JNBE (Jump if Not Below or Equal): Jumps if (CF = 0 and ZF = 0).
• JL (Jump if Less): Jumps if (SF != OF).
• JLE (Jump if Less or Equal): Jumps if (SF != OF or ZF = 1).
• JNL (Jump if Not Less): Jumps if (SF = OF).
• JNLE (Jump if Not Less or Equal): Jumps if (SF = OF and ZF = 0).
• JP/JPE (Jump if Parity/Even Parity): Jumps if Parity Flag (PF) is set (PF = 1).
• JNP/JPO (Jump if Not Parity/Odd Parity): Jumps if Parity Flag (PF) is not set (PF = 0).

Integer Addition and Subtraction

start:
mov al, 5
mov cl, 2
add al,cl

start:
mov dx, 0
mov ax, 0083
mov bx, 2
div bx

start:
mov ah, 255
mov bh, 254
xor ah, bh

• Operation List

ADD X1,X2    ;將X1 X2的數字相加並存入X1中
SUB X1,X2    ;同 上 ，只 是 變 減 法 MUL BXAX去乘BX
INC X1     ;X1的數字加1 ，並放回X1 D E C X 1 同 上 ，但 變 減 1
NEG X1     ;將X1的數字變為2的補數
OR X1,X2     ;X1,X2 去做OR邏輯運算，並將結果放回X1
AND X1,X2     ;同上只是去做AND邏輯運算
TEST X1,X2     ;同上，他是去做AND邏輯運算但比較特殊的是他不會把結果存入X1中
END     ;表示程式結束處 DB[字串，數值]去定義一個位元組的資料不影響旗標的程式=〉
            ;移動資料的程式(註記碼) like: MOV AX,BX/POP AX/PUSH AX

Exam

EM1
EM2