Yes Rauf it works.

I have used similar approach.
If you are using four ports to different pins input then o'course you will have to use one common (ored) to generate the interrput.

But if all four pulses have to land on the same pin, then it makes your case even simpler and no use of interrupt.

Just keep waiting till the pulse Changes
its state (from H to L or otherwise), you know what to do,

if you allow me it may be like this,

pulse bit p1.0 ; or any you like

jb pulse,$ ; wait
setb tr0 ; start timer
jnb pulse,$ ; wait again
clr tr0 ; stop timer

mov a,tl0 ; copy time low byte to acc
call send ; use a serial routine to
; send the byte to terminal

copy a,th0 ; repeat for high byte also
call send
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You will have to correct the result and compensate for time lost during execution of the code its self.

If the pulses are of small width then use micro crystal of higher frequency.

Good Luck

Babar/

PS:

You aren't getting back to direct mails ??