Casio 121-L Desktop Calculator (LSI)
Casio 121-L four-function desktop calculator
The Casio 121 series is a family of compact desktop calculators introduced by Casio in the late 1960s and early 1970s, which competed against Sharp's QT-8 line of calculators. As indicated by their model numbers, 121 series machines have a 12-digit display. Earlier machines are fitted with Nixie tubes, while later iterations are equipped with discrete VFDs. The 121-A was the first member of this series, and featured a relatively compact but unusual landscape form factor with an asymmetrical layout and a woodgrain bezel. The subsequent 121-B and 121-K saw improvements in IC integration, but retained the 12-tube Nixie display.
Introduced in 1971, the Root 121-A is perhaps the most sophisticated member of the 121 family, featuring a concise NEC chipset capable of performing the square root function. Unlike the original 121-A, the Root 121-A has a more conventional form factor, with a rugged black plastic case and an aluminum bezel.
The model 121-L is a later member of the family, which introduced VFD technology to the series. The 121-L was initially manufactured in a 14-chip version and later in the 12-chip version featured in our collection. Unlike the Root 121-A, the 121-L is equipped with a memory function. Despite differences in technology and capabilities, the Root 121-A and 121-L share the same form factor and aesthetics.
Like many Japanese desktop calculators from the era, the Root 121-A and 121-L are equipped with a magnetic reed switch keyboard. The power supply in these units has multiple taps which can be used to convert the unit for international usage or when importing with no other required modifications.
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