Assembly language program for take a string as input and print it as output.
org 100h
STRING DB 11DUP(0)
mov cx,0000h
;jay: mov ah,01h
jay: mov ah,1
int 21h
MOV [STRING],AL
INC STRING
inc cx
cmp cx,0010h
JNZ jay
;jha:mov cx,0010h
JHA:mov ah,2
;int 21h
;pop ax
mov AL,[STRING]
out dx,al
inc cx
int 21h
DEC STRING
dec cx
cmp cx,0000h
jnz jha
end
Operating system important questions.
Difference between logical and physical address
Logical address-->Address generated by C.P.U is called logical address.
Logical address has two fields
EX. If we have four segments seg-0,seg-1,seg-2 and seg-3 and each has equal length of 500 then 0
,0103,2400,3500,2450 are valid logical addresses.
Physical address-->Address seen by the memory unit that can be loaded M.A.R(Memory address register) is called physical address.
Above it has has been discussed that logical address has two parts to convert a logical address into physical address we use segment table the correspomding base of
segment table is added with offset of logical address.
EX. If logical address is 0103 and seg-0 has base value in seg table is 125 then
Physical address 103+125=228.