Installing software

I am a bit unclear of the limitations of my knoppix installation. It is a
pentiuim 233mmx with 168 mb ram. Knoppix runs off the cdrom with a
persistent home and myconfig located in a 128mb sandisk memory card. 
Should I run apt-get update with this setup ? Can I install additional 
software with apt, for example hylafax ?

I am new to knoppix on cdrom. My previous experience has been with a
hard drive installation of knoppix. 

Brian