Brand: CASIO
Model: PB-100
Type: BASIC-programmable Pocket Computer
Picture: CASIO PB-100
Batteries: CR 2032 x 2
Lifetime: Introduced: 1982
Terminated: unknown
Notes: This Pocket Computer came right after the FX-702P. Whilst CASIO itself called said predecessor a Programmable Calculator in its manual, the CASIO PB-100 is actually called a Pocket Computer.
From its manual:

Thank you very much for purchasing the CASIO PB-100. This unit is a "handy type" personal computer which is excellent for those who are beginning to learn about computers.
There is also a TANDY version of this device, the TRS-80 PC-4.

It can be used as a calculator in RUN mode. Scientific functions have to be typed to use them. Calculations, after being evaluated, can not be replayed, there is however an "ANS"-key to produce the last result and use it in new calculations.

When performing calculations, true algebraic logic is used, so "- 12 + 6 * 9" gives the correct answer of "42". Brackets can also be used, and they do not need to be closed, so "1 * ( 2 + 3" is correctly evaluated to "5".

The display can be configured to display a specific required accuracy. This is done using the "SET"-command. "SET E" to determine the number of effective positions. "SET F" can be used to set the number of decimal positions. Use "SET N" to return back to "normal".

For programming, the built-in memory of 1 kB leaves 544 programming steps and 26 memories. Using the "DEFM" operation the memory can be segmented exchanging programming steps for up to 94 memory locations. There is also a 1 kB OR-1 optional RAM pack expanding the default configuration to 1,568 programming steps and up to 222 memory locations.

The standard 26 variables A-Z can only be used as either a number or a string. String variables can store a maximum of 7 characters. There is one special string variable called "$" however, which can store 30 characters. This is handy when used in operations where strings are added together.

For programming there are 10 distinct program areas, P0 - P9. Programs can be edited or erased in WRT mode. To erase the selected program type "CLEAR". To erase all programs type "CLEARA".

As usual a BASIC program use line numbers. The maximum line length (including the line number) is 62 characters. Editing programs is a little cumbersome due to the lack of up/down arrow keys. Type "LIST" to start listing, approximately 2 seconds per line. Listing can be stopped using the "STOP"-key and resumed by pressing the "EXE"-key.

A neat feature is how subroutines work. They can be nested a maximum of 8 levels deep. A subroutine call can be to a line number, or to one of the other programs, e.g. "GOSUB #4" will call P4 as a subroutine. To make it even more powerful, the value passed to "GOSUB" can also be the result of a calculation!

Note that there is a slight colour hue on this Pocket Computer’s scan, that is due to the fact that the original plastic protective foil is still present. I didn’t feel like pealing it off.


For an extra 1 kB of memory there is the OR-1 RAM pack.

There are various interfaces for this calculator. There is the FA-3 and FA-5 cassette-interfaces, the FP-12 series of mini-thermoprinters, the FP-40 printer and a SB-2 link cable. These details come from this page on (link valid 2024-01-13).