Hi everybody in that forum !

I´ve connected a keyboard with 16 digits
to a 80C535 via a 74HC154 ( 4 to 16 Line
decoder ) on Port 4.0 to 4.3 My System works at 12 Mhz.
The result of a keypressed action is on Port 4.4 . I´ve a Routine to get the
pressed Key:


keyscan: MOV A,P4 ;16 digit Routine
ORL A,#00011111B ; set keylines
MOV P4,A ;write back to Port

decode:
MOV A,P4 ; read PORT4
ANL A,#00001111B ; mask Portlines
JNB P4.4,detect ;check if key pressed
JZ NODECT ; exit if 0
DEC P4 ; dec. PORT
SJMP decode

detect: .... continue here


my question is, how to get on with the
Program by pressing the buton "entry"
= 11 to get a -- entry for 2 Digits
or again for --- 3 Digits. And take the
entry with the "*" Key = 12.
With storing it for ex. in pressedkey ..

Does anyone know how to do this ...

Thanks ..

Stefan