Download pcmcia-source, by typing
| apt-get install pcmcia-source | 
| /usr/src | 
| pcmcia-cs.tar.gz | 
You now need to gunzip the file by
| gunzip pcmcia-cs.tar.gz | 
| tar xvf pcmcia-cs.tar | 
You should see pcmcia-source unpacked into the directory
| /usr/src/modules/pcmcia-cs |