You can do it even faster by doing it the way Charles originally showed you, (did you REALLY try that and it didn't work?) in other words:
Code:
ShadowC VAR BYTE
ShadowC = PortC

ShadowC.0=1
ShadowC.1=1
ShadowC.2=1
ShadowC.3=1

PortC = ShadowC
/Henrik.