• TYPE: Compact Flash Type 1
• SIZE: 2GB maximum capacity. Cards larger than 2GB are not compatible and will not work.
• QUALITY: Using major brands such as Sandisk, Panasonic, Kingston and Lexar is preferred.
• SPEED: Using slow speed cards that are 40X speed or slower and/or 6 MB per second transfer rate or slower is recommended.
  

Note that because slower speed CF cards have become increasingly difficult to find, we don't have a direct resource for acquiring new cards.