Prices of CompactFlash cards having dropped considerably over the past year or so, the author decided to design a parallel PC interface that allows data or programs to be written into one of these handy solid-state memories using MCS-BASIC52.CompactFlash (CF) cards are gaining popularity every day, probably because the vast majority of digital cameras employ them for mass data storage, and, in a more general sense, because the phenomenon ‘digital camera’ itself is taking the world by storm. Thanks to ongoing developments in CF technology, the memory capacity rises while prices drop.