Casio Mini-8

The Casio Mini-8, also known as the Y-800, is a handheld calculator manufactured by Casio Computer Company Ltd. in Japan around 1975. This horizontal format calculator features a two-piece case made of dark brown and light beige smooth plastic, with a slightly wedge-shaped design. The raised and tilted display area houses an 8-digit blue VFD display, while the keyboard area is surrounded by a brushed aluminum inset with Casio’s typical key frames.

Measuring approximately 148mm x 72mm x 23.8mm (w,h,d) and weighing 112g excluding batteries, the Casio Mini-8 is powered by two AA batteries or an optional AD-2S adapter. Its compact size and portability make it a convenient choice for basic calculations.

Under the hood, the Mini-8 is powered by a NEC uPD976C H5X056 28-pin DIL CPU and an E6535A 5L6C3G 8-digit VFD display tube. The calculator’s construction features a keyboard board (ref B8R-E4A2) attached to the front with five screws and connected to the floating CPU board (ref B8R-1A) via twelve strong wires. While it is possible to open the case, caution is advised to avoid damaging the calculator.


  • The (C) button clears the last entry, while the (AC) button clears the entire calculator.
  • Overflow on number input is suppressed, ignoring the ninth digit when typing a nine-digit number.
  • Overflow errors are flagged with “E.” in the first (right-most) digit and are not recoverable.
  • Divide by zero results in “E.” displayed in the first digit and is not recoverable.
  • The function of the (CNG) key is unknown.
  • There is no constant function.
  • Negative numbers are shown with a “-” in the immediate left digit, but are limited to seven digits due to the lack of a ninth digit.

The Casio Mini-8 is a solidly built, early horizontal calculator from Casio, offering basic arithmetic functions and percentages. Its compact design and straightforward operation make it a notable addition to any calculator collection, despite its limited functionality by modern standards.

Right Now on eBay 
Clicking a link to eBay may result in a referral commission being paid if a purchase is made.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.