Assume in MASM

[ArtemESC]

Help me, please...
Why my code incorrect?
When i run debugger, my program start to work from first segment instead code segment?

title CharProcessing

text  segment
txt   db 200 dup (?)
text  ends

stack segment
S    db 100 dup (?)
stack ends

INCH  macro x
mov  ah, 7h
int  21h
mov  bl, al
mov  x,  bl
     endm

OUTCH macro c
mov  dl, c
mov  ah, 2h
int  21h
     endm

FINISH macro
mov  ax, 4C00h
int  21h
     endm

NEWLINE macro
OUTCH 13
     endm

code segment
assume cs: code, ds: text, ss: stack
; set start params
OUTCH '>'
cld
mov   ax, text
mov   ds, ax
mov   ax, stack
mov   ss, ax
mov   di, 0h
mov   si, 0h

; read text
Read:
INCH  al
cmp   al, '.'
je    Next
stosb
jmp   Read

; print source text
Next:
lodsb
OUTCH al
cmp   si, di
jbe   Next

; test
mov   al, [di]
cmp   al, 'A'
jb    Prop2
cmp   al, 'Z'
jg    Prop2
mov   si, 0h
Next2:
cmp   al, ds: [si]
je    Prop2
inc   si
cmp   si, di
jb    Next2
call  rule1
jmp   Result

Prop2:
call  rule2
jmp   Result

; rule # 1
rule1  proc
mov   si, 0h
L:
lodsb
cmp   al, 'a'
jb    Cont
cmp   al, 'z'
jg    Cont
add   al, 32
mov   ds: [si], al
Cont:
cmp   si, di
jbe   L
ret
rule1  endp

; rule # 2
rule2  proc
mov   si, di
mov   cx, si
std
L1:
lodsb
push  ax
loop  L1
cld
mov   cx, di
mov   di, 0h
L2: 
pop   ax
mov   ah, al
stosw
loop  L2
ret
rule2 endp

; print result code
NEWLINE
Result:
mov   cx, di
L:
lodsb 
OUTCH al
loop  L

FINISH     
code ends

end

[asmfan]

Artem,
why dont you declare the start label? basically all .asm files terminated by <END StartLabel>

[ArtemESC]

>>asmfan
     Do you speak Russia? I viewed you blank and had noted you location.

    In theory labels isn't requested.

[asmfan]

Artem,
i speak a little bit;)
...but in practice they (labels) are needed. or otherwise you'll get what you have now (execution from the first byte of the first section).
use <END Start>

[ArtemESC]

 Really label is needed...
   
  Thanks!

So, I don't understand meaning of  "assume"...

[Mark Jones]

So, I don't understand meaning of  "assume"...

Here is a 32-bit implementation of ASSUME. Maybe this will help.

Code Select Expand


SOME_STRUCT STRUCT
    Element1  DD  ?
    Element2  DD  ?
    Element3  DD  ?
SOME_STRUCT ENDS

.data?
    MyStruct1 SOME_STRUCT<>
    MyStruct2 SOME_STRUCT<>
    MyStruct3 SOME_STRUCT<>

.code
    ASSUME EAX:PTR MyStruct1
    MOV [EAX.Element1], 10101010h
    MOV [EAX.Element2], 12345678h
    MOV [EAX.Element3], 87654321h

    ASSUME EAX:PTR MyStruct2
    MOV [EAX.Element1], 10101010h ; ...etc.

    ASSUME EAX:NOTHING


There is an explination of the various ASSUME functions in the MASM32 v9.0 installation under \masm32\help\masm32.hlp

[Rockphorr]

Really label is needed...
   
  Thanks!

So, I don't understand meaning of  "assume"...

Assume указывает какой сегмент к какому сегментному регистру относится,
в простых программах можно не указывать, но иногда бывают "тяжелые" случаи когда Assume необходим, как например в листингах BIOS которые приводила IBM; в книге Пильшикова "Ассемблер" довольно внятно про нее рассказано