The Casio PB-1000 was an original, well designed and powerful pocket computer for its time.
On top of its standard QWERTY keyboard, a row of sensitive keys allowed fast
scientific calculations, menus access and text editing. The 4-line LCD display
also had 16 sensitive areas.
The computer could be programmed either in Basic or Assembly language. The C61 Basic interpreter, based on Japan Industrial Standard BASIC, had a wide range of built-in mathematic, trigonometric and statistic functions. Assembly programs had to be typed by using the built-in editor then compiled. The user's manual gave little information about CPU instructions and, oddly enough, Casio and it's distributors never released a full description of the whole CPU's instructions set, although Casio published an incomplete "Technical Reference Manual".
The processor was an Hitachi HDS61700. It contained a small amount of ROM and RAM, as well memory management and I/O circuitry. The memory was managed like a virtual disk. Several Basic or Assembly programs as well as ASCII text could be stored together in the same RAM area.
Two extensions were released for the PB-1000, the FA-7 Serial, Parallel and tape recorder interface, and the rare MD-100 3.5" floppy drive unit.
The PB-1000 was followed by the PB-2000 which lost the lift up display but had the unique feature of being programmable in ANSI C language.
