The CASIO PB-100 series

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 This series includes pockets derived from the PB-100
 Commonalities :

 Size : 165 x 71 x 10 mm

 A 12-digit screen

 a programming language very rudimentary
 They differ one from the other :

 by standard or extended memory (OR-X modules)

 by the addition of an extra function key F

 by the availability of S+EXE combination ("previous" function)

 by the str$( ) function

 by the DATA BANK functions

 The keys are whether black whether white and the hull presents various tints.

 F key

 The F key permits direct access to some mathematicals functions written besides character keys.

 When it is not available, it is possible to add the F key by making a hole on the right of the S key and putting a spare key. This has not been studied on models including Data Banks funtions.Watch programs to download

 The FX models have F Key, the PB ones haven't, like for the PB-410 series.
 The "Previous" key

 On models presenting a little triangle above the Enter key, the S+EXE combination allows to move back in the listing (mode 1).

 On data bank models, this combination allows to edit previous data while editing.
 A special model with a familiar look : the UCOM