??6.5?????Z=((X Y)*8-X)/2

About This Presentation

Title:

**??6.5?????Z=((X Y)*8-X)/2**

Description:

Title: Author: WANG Last modified by: Billgates Created Date: 4/30/2003 2:16:35 PM Document presentation format: – PowerPoint PPT presentation

Number of Views:14

Avg rating:3.0/5.0

Slides: 41

Provided by: wang97

Category:

Tags:

more less

Transcript and Presenter's Notes

Title: ??6.5?????Z=((X Y)*8-X)/2

1
?6?
2
?6?6.2 ??????

6.2.1 ??????
???????????????,???????????????,???????
?????????????
?????????????????

??6.5?????Z((XY)8-X)/2 ??6.6
?????????????,????16 ??????ASCII???
3
?6??6.6(2) ???

???
ASCII db 30h,31h,32h,33h,34h,35h,36h,37h,38h,39h
??0 9?ASCII?
db 41h,42h,43h,44h,45h,46h
??A F?ASCII?
hex db 04h,0bh
??????

4
?6??6.6(2) ???

???
mov bx,offset ASCII
BX??ASCII??
mov al,hex
AL????16???
????ASCII??????
and al,0fh
???4?????,?4??0
xlat
??AL?DSBXAL

XLAT
5
?6??6.6(2) ???(?)

mov dl,al ????DL?AL
mov ah,2 02?DOS????
int 21h ????ASCII???
mov al,hex1 ??????????
and al,0fh
xlat
mov dl,al
mov ah,2
int 21h

XLAT
6
?6?6.2.2 ??????

??????????????????
??????????,?CMP?TEST???????????
????Jcc?JMP????????
?????
?????
?????
?????

7
?6??????

??????,???????????
????????????????????

??????
8
?6???AX?????????

cmp ax,0
jge nonneg ????(AX0),??
neg ax ?????,??
nonneg mov result,ax ????

?????? cmp ax,0 jl yesneg ????(AXlt0),?? jmp
nonneg yesneg neg ax ?????,?? nonneg mov
result,ax ????
9
?6??????

?????????2??????,???????1??????
???1???????????JMP?????2?????

????BX????
10
?6???BX????

shl bx,1 BX?????CF??
jc one CF1,?????1,??
mov dl,30h
CF0,?????0DL?30H0
jmp two ???????????
one mov dl,31h DL? 31H1
two mov ah,2
int 21h ??

???JNC??JC
11
?6???BX????(?)

shl bx,1 BX?????CF??
jnc one CF0,?????0,??
mov dl,31h
CF1,?????1DL?31H1
jmp two ???????????
one mov dl,30h DL? 30H0
two mov ah,2
int 21h ??

????????
12
?6???BX????(??)

mov dl,0 DL?30H0
shl bx,1 BX?????CF??
jnc two CF0,?????0,??
mov dl,1
CF1,?????1DL?31H1
two mov ah,2
int 21h ??

??????,???????????

13
?6???BX????(???)

mov dl,0
shl bx,1 BX?????CF??
adc dl,30h
CF0,DL?030h030H0
CF1,DL?030h131H1
two mov ah,2
int 21h ??

14
?6??????
????????????????????,????????????????
or ah,ah cmp ah,0 jz function0 dec ah cmp
ah,1 jz function1 dec ah cmp ah,2 jz function2
15
?6?6.2.3 ??????

?????????????????,????????
??????????3???
??????????????????,???????????????
???????????????,????????????????
????????????????,????????

??????
16
?6?????

??????????????????
???????????????,??????????,????????
?????????,WHILE_DO
?????????,DO_UNTIL
??????????????,?????????,????
??????
??????

??
17
?6????????????
18
?6? ??????

??????????????????
????????LOOP?JCXZ??
?????????????????CX
???
?????LOOP???CX?1???????0

19
?6???????BL??
???

mov cx,8 CX?8(????)
again shl bl,1 ???CF,???????
mov dl,0 MOV?????CF
adc dl,30h DL?030HCF
CF??0,?DL?' 0 '
CF??1,?DL?' 1 '
mov ah,2
int 21h ??
loop again
CX?1,??CX???0,???

???
?????? ??????
20
?6???????

??????????????????????
???????????????????
??????????????????????,????????????????????????,??
????????

21
?6????0??????

???
string db 'Let us have a try !',0
???
mov bx,offset string
again mov dl,bx
cmp dl,0
jz done ?0??
mov ah,2 ??0,??
int 21h
inc bx ???????
jmp again
done

?????? ??????
22
?6?6.2.4 ?????

??????????????????,????????????????,??????
??????????????,????????,????????
???(????)????CALL???????(?????)
???????RET???????

23
?6?1 ???????

?????,????????????PROC?ENDP??,????
??? PROC NEARFAR
???
??? ENDP
???????????????????????,???????
NEAR??(?????)??????????????????
FAR??(?????)???????????????????

24
?6?1 ???????
???? XSEG SEGMENT SUBT1
PROC FAR
RET SUBT1 ENDP
CALL SUBT1 XSEG ENDS YSEG SEGMENT
CALL SUBT1
YSEG ENDS
?????????? CSEG SEGMENT MAIN PROC FAR
CALL SUBT
RET MAIN
ENDP SUBT PROC NEAR
RET SUBT ENDP CSEG ENDS
25
?6??????????

????????????????
????????RET???????,?????CALL???????
?????????????????????,???????
???????????????????,????????????
?????????????????,???????????????(??DOS??????END??
??),?????????????????

26
?6??????????(?)

???????????
?????????????????,???????????(????DS),????????????
??(??CS??)
????????????,????????(??RET??)???,??????????????
???????????????????
?????????????

27
?6?????????

???HTOASC????????ASCII?
HTOASC proc
push bx
mov bx,offset ASCII
and al,0fh
xlat CSASCII ??AL?CSBXAL
pop bx
ret
???
ASCII db 30h,31h,32h,33h,34h,35h,36h,37h,38h,39h
db 41h,42h,43h,44h,45h,46h
HTOASC endp

28
?6???????

???HTOASC????????ASCII?
HTOASC proc
and al,0fh
cmp al,9
jbe htoasc1
add al,37h ?A F,?37H
ret ?????
htoasc1 add,30h ?0 9,?30H
ret ?????
HTOASC endp

29
?6?2.????

???????????????????
????(????) ?????????,?????????
????(????) ????????????????
???????
?????????
????????????
?????????
???
????
??

30
?6? ????????

???????????????????,??????????????????
???????????,?????????????????,????????????
?????????,???????????????????,????????????????????
?,?????????

dpchar
dpstri
HTOASC
31
?6? ?????????

???????????????????????????(????)??????
??????????????????,????PUBLIC?EXTREN??
???????????????,????????
??????????,?????????,????????????????????????????

32
?6? ???????????

??????????????????,???????,?????????,???????????
????????????????,??????,???????????????????
????

33
?6????????

???????????????????????????????,?????????????????
??????,???????????
?????????????,??????????????????????????????????

34
6.4 DOS?BIOS??????

????????
DOS??
?????20H3FH???????20H27H?2FH,?????
ROM BIOS??
??????10H1FH?
????
?????40HFFH,??????????????????????

35
6.4.1 DOS???????

DOS????
?INT 22 H?INT 23H?INT 24H???????DOS?????,??????
??
DOS?????
?INT 20H?INT 21H?INT 25H?INT 26H?INT 27H?INT
2FH 6???????????,?????????????

??????25?26H
?????????????
????
AL??????
CX???????
DX??????????
DSBX????????

MOV AL,0 MOV CX,7 MOV DX,5 MOV BX,1000H INT
25H JMP 0
37

??????20?27H
20H?????
27H???????,??????DOS????????,?????????????????,???
????????????
?????????
INT 2FH?????????????PRINT
??????
21H??????????????????????????,????????????????????
?????

38
6.4.2 BIOS????

?????????BIOS
???DOS???I/O????,????????????
???I/O?????????,?????????DOS??I/O??????
??
???????INT 16H
????INT 10H
???????INT 17H

39
?6?????

????????????
???????????????????????????
??????????????????????????
???????????
EQU/-/DB/DW/DD??/DUPORG/?OFFSET/SEG/PTR.MO
DEL/.STACK/.DATA/.CODE/ENDPROC/ENDP

40
?6?????(?)

?????????????????????
??????????
?????,??(????????)?ASCII?BCD??????????(09?AZ?a
z)??????????????????????????????????????

41
dpchar????????

???
mov al,? ?????????
call dpchar
?????AL????
dpchar proc
push ax
push bx
mov bx,0
mov ah,0eh
int 10h
pop bx
pop ax
ret
dpchar endp

???????AL,??? ?????
42
dpstri????????

???dpstri??DSSI??????
dpstri proc
push ax
dps1 mov al,si
inc si
cmp al,0
jz dps2
call dpchar
jmp dps1
dps2 pop ax
ret
dpstri endp

???????DSSI,??? ?????
43
HTOASC????????

???HTOASC????????ASCII?
HTOASC proc
push bx
mov bx,offset ASCII
and al,0fh
xlat CSASCII
pop bx
ret
ASCII db 30h,31h,32h,33h,34h,35h,36h,37h,38h,39h
db 41h,42h,43h,44h,45h,46h
HTOASC endp

???????AL,??? ???????AL,???

Write a Comment

User Comments (0)

About PowerShow.com

??6.5?????Z=((X Y)*8-X)/2 - PowerPoint PPT Presentation

??6.5?????Z=((X Y)*8-X)/2

Title: Author: WANG Last modified by: Billgates Created Date: 4/30/2003 2:16:35 PM Document presentation format: – PowerPoint PPT presentation

**??6.5?????Z=((X Y)*8-X)/2**