Casio V.P.A.M. calculators

Casio V.P.A.M. calculators are scientific calculators made by Casio which use Casio's Visually Perfect Algebraic Method (V.P.A.M.), Natural Display or Natural V.P.A.M. input methods.

V.P.A.M. is an infix system for entering mathematical expressions, used by Casio in most of its current scientific calculators. In the infix notation the precedence of mathematical operators is taken into account. According to Casio, in V.P.A.M. calculations can be input exactly as they are normally written. Functions, operators and symbols are shown on the calculator display and calculations are performed according to operator precedence.

History
The V.P.A.M. brand was first used in 1994 when the fx-991S and other scientific calculators from the "S" series were released in Japan. In 1998, the Casio fx-991W model used a two-tier (multi-line) display and the system was termed as S-V.P.A.M. (Super V.P.A.M.). The model featured a 5×6-dot LCD matrix cells on the top line of the screen and a 7-segment LCD on the bottom line of the screen that had been used in Casio fx-4500P programmable calculators. The S-V.P.A.M. system was also used in the other W series models and also the MS series of calculators that followed. V.P.A.M. is similar to the Direct Algebraic Logic (D.A.L.) used by Sharp in some of their scientific calculators.

The fx-82ES introduced by Casio in 2004 was the first calculator to incorporate the Natural Textbook Display (or Natural Display) system. It allowed the display of expressions of fractions, exponents, logarithms, powers and square roots etc. as they are written in a standard textbook. Natural Display uses natural representation of mathematical expressions and formulas through a 96×31 dot matrix LCD display. Casio uses the term Natural V.P.A.M. for the fx-ES Plus series of calculators which are the upgraded version of the fx-ES series.

In early 2015, Casio introduced a new line of calculators called ClassWiz (stylized as C L A S S W I Z) for different markets, featuring a high resolution (192×63) dot matrix Natural Textbook Display and incorporating spreadsheet functions in some models. This series of calculators is called the fx-EX series and it succeeds the fx-ES Plus series of calculators.

In late 2022, Casio introduced a second generation of ClassWiz line, called fx-CW. Calculators in this line have an updated user interface, and come with 4-gradation displays.

List of calculators
Note: Italic figures in parentheses indicate the year of introduction, e.g.: (c. 1994)

V.P.A.M. (Visually perfect algebraic method)
Models:
 * fx-991S / 570S / 911S / 992S (c. 1994)
 * fx-115S / 100S / 122S (c. 1995)
 * fx-993S (c. 1996)
 * fx-300S (a simplified 8+2 digit version)



W-series
Changes to S-series calculators include: Models:
 * 2-line LCD display featuring 5×6-dot matrix cells top line and 7-segment LCD bottom line that had been used in Casio fx-4500P programmable calculators (used 5×7-dot matrix cells).
 * fx-991W / 570W / 115W / 100W / 115WA (c. 1998-99)
 * fx-82TL / 83W / 85W / 85WA / 300W / 350TL / 83WA / 270W (c. 1998-99)

MS-series
Revised variants of W Series of calculators including new functions such as: Non-programmable models:
 * Relocation of multiple functions into menus, previously featured in Casio fx-5500LA, but function is selected by numeric keypad
 * Multiple statement recall
 * fx-991MS / 570MS / 115MS / 100MS / 95MS / 85MS / 350MS / 82MS (early 2000s)
 * fx-912MS (Japanese version of the fx-115MS)
 * fx-300MS (U.S. model)
 * OH-300MS (Overhead projection model), fx-100AU (Australia specific)
 * fx-500MS (Vietnam)
 * fx-290 (Japan)
 * fx-220 PLUS (International)

Programmable models:
 * fx-3650/3950P (International)
 * fx-3650P II (International)
 * fx-50F PLUS (International)
 * fx-50FH (Hong Kong)
 * fx-50FH II (Hong Kong)
 * fx-72F (Japan)

Natural Textbook Display
Revised version of the MS Series including the following changes:
 * Multi-line 96×31 dot matrix displays, but character cells are connected by dots like graphing calculators
 * The ability to display and edit mathematical formulas in more visual formats
 * Revised design of function menu interface, previously featured in Casio fx-4800P
 * No engineering symbol (SI prefixes) input or display facility, which was available in certain MS / W / S series models (fx-100, 115, 570 and 991MS / W / S).
 * Use the nX-U8/100 based OKI ML610901(B) microcontroller.

Model-specific features include: Models:
 * Numerical integration uses Gauss–Kronrod quadrature formula
 * fx-991ES / 570ES / 115ES (c. 2004)
 * fx-500ES / 350ES / 300ES / 85ES / 83ES / 82ES (c. 2004)
 * OH-300ES (Overhead projection model)
 * FC-100/200V (financial functions)
 * fx-5800P (Programmable)

Natural V.P.A.M.
Original Models: Second edition models:
 * fx-82 / 85 / 95 / 350 / 570 / 991ES PLUS (c. 2008-09)
 * fx-82AU PLUS, fx-82AU PLUS II, fx-100AU PLUS (Australia)
 * fx-82ES PLUS A (China, simplified Chinese messages)
 * fx-115 / 300ES PLUS, fx-55 PLUS (U.S. and Europe)
 * fx-991ES PLUS C (Canadian version of fx-115ES PLUS)
 * fx-82 / 85 / 86 / 87 / 991DE PLUS (Germany)
 * fx-92 Collège 2D+ (France)
 * fx-92B Collège 2D+ (Belgium)
 * fx-83 / 85GT PLUS (EU, UK)
 * fx-82 / 991ZA PLUS (South Africa)
 * fx-82 / 350 / 570 / 991LA PLUS (Latin America)
 * fx-373 / 913 / 573 / 993ES (2008) (Japan)
 * fx-375 / 915 / 995ES, fx-520AZ STUDY CAL (2012) (Japan)
 * fx-500 / 570VN PLUS (Vietnam)
 * fx-95 / 96SG PLUS (Singapore)
 * fx-991ID PLUS (Indonesia)
 * OH-300ES PLUS (Overhead projection model)
 * fx-FD10 Pro (International civil engineering model)


 * fx-82 / 85 / 95 / 350 / 570 / 991ES PLUS 2nd edition
 * fx-82AU PLUS II 2nd edition, fx-100AU PLUS 2nd edition (Australia)
 * fx-82ES PLUS A 2nd edition (China)
 * fx-115 / 300ES PLUS 2nd edition (U.S.)
 * fx-991ES PLUS C 2nd edition (Canada)
 * fx-87DE PLUS 2nd edition (Germany)
 * fx-375ES A (Japan)
 * fx-82 / 350 / 570 / 991LA PLUS 2nd edition (Latin America)
 * fx-570VN PLUS 2nd edition (Vietnam)
 * fx-82 / 991ZA PLUS II (South Africa)
 * fx-991ID PLUS 2nd edition (Indonesia)

The CPU found in those models is based on the nX-U8/100 architecture.

First version (X series)
Changes to the ES PLUS series include: Model-specific features include:
 * Standard 192×63 display
 * Icon-based mode menu previously used on Casio fx-9700GE graphing calculators
 * Mode-specific functions are accessible via a unified function key as in fx-4800P
 * Scientific constants and conversion functions are grouped into categories
 * Multilingual messages (excluding EX models and DE X models)
 * QR code export (excluding CN X models, VN X models and fx-530AZ STUDY CAL)
 * Multiline display supports up to 6 rows (excluding JP series, fx-530AZ STUDY CAL and fx-580VN X)
 * Vector mode now supports maximum 4-variable vectors and 4 user-defined vector storage
 * Matrix mode now supports maximum 4×4 matrices and 4 user-defined matrix storage
 * New spreadsheet mode (excluding CN X and VN X models)
 * Simultaneous linear equation solver supports up to 4 variables
 * Polynomial equation solver supports up to 4th degree equations and inequalities
 * Engineering symbols display and entry previously found in MS / W / S / D-series calculators
 * Periodic table mode with atomic weight information (fx-JP900, fx-991CE X and fx-991RS X only)

Models:
 * fx-JP500 / 700 / 900 and fx-530AZ STUDY CAL (late 2014) (Japan)
 * fx-82 / 85 / 350 / 570 / 991EX (early 2015) (International)
 * fx-82 / 85 / 87 / 991DE X (Germany)
 * fx-82 / 85 / 350 / 991CE X (Central Europe)
 * fx-83 / 85GT X (2019) (EU, UK)
 * fx-92 / 92+ Spéciale Collège (France)
 * fx-92B Spéciale Collège (Belgium)
 * fx-82 / 350 / 570 / 991SP X I/II Iberia / fx-85SP X II Iberia (Portugal, Spain)
 * fx-82 / 350 / 570 / 991LA X (Latin America)
 * fx-82 / 95 / 570 / 991AR X (2015) (Middle East, Arabic Africa)
 * fx-82 / 95 / 350 / 991CN X 中文版 (Chinese Edition) (2014) (China)
 * fx-580VN X (Vietnam)
 * fx-97SG X (Singapore)
 * fx-991RS X (Serbia)

Second version (CW series)
The series was originally called the Z series, but was later changed to the CW series. Changes to the ClassWiz X series include:


 * The screen resolution remains at 192x63 pixels but now features 4-level grayscale display
 * Cursor navigation completely replaces the previous method of using numeric keys to select menu options
 * Added the Math Box application for mathematical exploration in most models
 * Significant changes to the keyboard layout: the ALPHA key is removed; navigation keys for cursor movement, page flipping, returning, and confirmation (OK) are added. However, the total number of keys is reduced from the original 50 to 48
 * Added Variable menu allows direct modification of variable values and supports storing results from the history log into variables
 * Added Function menu enables the definition of two functions and their utilization across multiple applications
 * Introduced CATALOG and TOOLS keys, where most functions and operations are accessed
 * The M variable is removed, replaced by the z variable
 * Except for CN CW models, variable store characters and multi-statement (i.e., colon ":") function are removed
 * Improved calculation precision to 23 digits and increased floating-point precision to 60 bits
 * The shutdown screen now includes not only the CASIO® logo but also the CASIO Education Statement slogan, Boost your Curiosity. On the CN CW series, this slogan is additionally presented in Chinese as "激发你的好奇心"
 * The performance of the nX-U8/100 microprocessor is increased by approximately 1.6 times
 * The sliding protective cover is replaced with a snap-on cover

Model-specific features include:


 * The previous Verify mode is no longer a standalone mode but dispersed across multiple modes, accessible within the Calculate, Complex, Table, and Equation applications
 * The CALC function, present in most earlier models, has been removed from the majority of models except for the fx-880BTG and JP CW series
 * The SOLVE function becomes a part of the Equation application
 * When solving cubic equations, the capability to find local maximum and minimum values is supported
 * The Statistics application now supports data sorting
 * Periodic table mode with atomic weight information (fx-JP900CW and fx-880BTG only)

Models:
 * fx-82 / 85 / 350 / 570 / 991CW (2022) (International)
 * fx-880BTG (Vietnam)
 * fx-JP500CW / JP700CW / JP900CW and fx-550AZ STUDY CAL (2023) (Japan)
 * fx-800DE Z(sample model), fx-800DE CW (2022), fx-82 / 85 / 87 / 991DE CW, fx-810DE CW (2023) (Germany)
 * fx-83 / 85GT CW (EU, UK)
 * fx-92 Collège (France)
 * fx-92B Secondaire (Belgium)
 * fx-82 / 85 / 991SP CW Iberia (Portugal, Spain)
 * fx-82 / 570 / 991LA CW (Latin America)
 * fx-82 / 95 / 350 / 991 / 999CN CW 中文版 (Chinese Edition) (2023) (China)
 * fx-8200 AU (Australia)
 * fx-82NL (Netherlands)
 * fx-570MY CW (2024) (Malaysia)