Free Pascal Operating System (FPOS) is a operating system consists of a minimal kernel built on FreePascal. It contains a Scheme implementation of a hard drive (ATA) driver, keyboard (PS2), serial (8250 UART), FAT32 filesystem and a small real time clock manager. The project was built to experiment with developement of operating system using a high level functional language to study the developement process and the use of Scheme to build a fairly complex system.