（汇编源代码 ）获取当前系统时间2008-04-30;========================================== ;A little assembly app that shows the current date and time. ;It can be done a lot easier, but this way you will ;see how to do some basic memory manipulation, and how to use "variables". ;========================================== .model small .stack ;=========================== ;Data segment starts here ;=========================== .data date_strdb"Current date is: yyyy-mm-dd", 0Ah, 0Dh, "$" time_strdb"Current time is: hh.mm.ss:xx", 0Ah, 0Dh, "$" min_sizedw？ padd_chrdb ？ ;=========================== ;Code segment starts here ;=========================== .code mainproc movax, seg @data ;First we get the data segment address movds, ax ;and store it into ds mov[min_size], 02h ;Results should always be at least two digits mov[padd_chr], "0" ;Use "0" as padding-character movah, 2Ah ;Then we call int 21h,2Ah, which will give int21h ;us the current date leadi, date_str ;Then we load the address of the date_str string adddi, 17 ;and set si to point at the first y in yyyy-... movax, cx ;Next we mov cx to ax and calltodec ;call todec incdi ;We skip the "-" character... xorax, ax ;Then we empty ax moval, dh ;And set the low-byte of ax to dh calltodec incdi ;Skip character in string... xorax, ax ;Empty ax moval, dl ;Set low-byte to dl calltodec ;Convert it to base10 leadi, time_str ;Now we load the time_str string adddi, 17 ;And set the correct pointer offset movah, 2Ch ;And then we call int 21h,2Ch int21h ;which will give us the current time xorax, ax ;Empty ax moval, ch ;Set low-byte to ch calltodec ;Convert it to base10 incdi ;Skip character moval, cl ;Set low-byte to cl calltodec ;Convert to base10 incdi ;Skip character moval, dh ;Set low-byte to dh calltodec ;Convert to base10 incdi ;Skip character moval, dl ;Set low-byte to dl calltodec ;Convert to base10 movdx, offset date_str;Now load offset of the date_str string into dx callprint ;And print the （modified） string movdx, offset time_str;Load offset of the time_str string into dx callprint ;And print the （modified） string movax, 4C00h ;Do a clean exit（error code=00） int21h ;=================================================================== ;todec - converts the contents of ax into base10 ascii character（s） ; of length bx ; min_size defines minimum length of result, and padd_char ; defines the padding character. ;The result（s） are stored at ds:di ;=================================================================== todecproc pushax ;Save all registers pushbx pushcx pushdx xorcx,cx ;Empty the POP counter movbx,10 ;Base divisor decloop: xordx,dx ;Set the high 16-bits to 0 divbx ;Preform division（dx=remainder, ax=quotient） inccx ;Increase the counter pushdx ;and save the remainder cmpax,0 ;If the quotient ！= 0 jnzdecloop ;then get one more number movbx, [min_size] ;Load min_size value into bx movdl, [padd_chr] ;Load padd_chr value into dl padd_result: cmpcx, bx ;Is cx >= min_size？ jgepoploop ;If so, proceed movbyte ptr ds:[di], dl;Else padd with padd_chr incdi ;and increase string pointer decbx ;decrease bx jmppadd_result ;and test for more padding poploop: popdx ;Get the number of the stack adddl,"0" ;and add "0" to it movbyte ptr ds:[di], dl;Modify the string at ds:di incdi ;Increase the string pointer deccx ;Decrease the loop counter jnzpoploop popdx ;Restore all registers popcx popbx popax ret ;And return from call todecendp ;=========================================================== ;print - prints the string pointed to by dx using int 21h,09 ;=========================================================== printproc pushax ;Save ax pushds ;and ds onto the stack movax, @data ;Then get the address of the data segment movds, ax ;and store it into ds movax, 0900h int21h ;and then print the message pointed to by dx popds ;Retrieve ds popax ;and ax from stack ret printendp mainendp endmain
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