（汇编源代码 ）获取当前系统时间

核心提示：;==;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,

;==========================================
;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