i connected those two vss pins to ground but i still got similar result as i mentioned on previous post. i think there somthing wrong with my code.You need to connect the two Vss pins to ground.
keyscan
clrf KEYPORT
;SCAN COLUMN 1
BSF KEYPORT, _C1
;KEY 1
BTFSC KEYPORT, _R1
RETLW .1
;KEY 4
BTFSC KEYPORT, _R2
RETLW .4
;KEY 7
BTFSC KEYPORT, _R2
RETLW .7
;KEY *
BTFSC KEYPORT, _R2
RETLW .10
Some of the crucial information being in chinese would be a problem for me.1x CD ROM (some wrote in chinese),including Chip datasheet,Schematic etc