Another feature-packed handheld computer by Casio, and this one’s expandable. The RC-4 module you see underneath packs a whopping 4K of Random Access Memory, giving you all the storage you could possibly need. Cautious programmers would probably use the card for backup purposes. This FX-750P offered two exansion slots; the FX-720P offered one. Coupled with the FA-20 mini-character printer and cassette recorder, this little thing became a formidable portable computer.