Get professional performance from the ultimate RPN scientific programmable calculator. Switch between RPN1 and algebraic entry-system logic at any time. The HP 35s features a two-line display, and the powerful HP Solve2 application.

The HP 35s Scientific Calculator is, as of 2007, the latest in Hewlett-Packard's long line of non-graphing scientific and programmable calculators. Although it is a successor to the HP 33s, it was introduced to commemorate the 35th anniversary of the HP-35, Hewlett-Packard's first pocket calculator (and the world's first pocket scientific calculator).

The HP 35s uses either Reverse Polish Notation (RPN) or Infix notation as input.

Other features of the HP 35s include[1]:

Two-line alphanumeric LCD display

26 memory registers

Scientific and statistical functions

Operation in decimal, binary, octal, hexadecimal

Equation solver (a feature first seen on the HP-34C)

Numerical integration (also first seen on the HP-34C)

Support for input and display of fractions

Complex number and vector calculations

Unit conversions and table of physical constants

Approximately 30 kilobytes of memory for programs and/or data

Although the HP 35s has far more functions, processing power, and memory than the original HP-35 which it commemorates, Hewlett-Packard has attempted to give the HP 35s the look of the original HP-35 and other HP calculators of that era. It also features the sloped-front keys for which HP calculators (although not the original HP-35) are well known.

The physical appearance and keyboard layout of the HP 35s is very different than that of its immediate predecessor, the HP 33s, but the two calculators are functionally almost identical. The primary differences are:

The HP 35s allows both label and line number addressing in programs. The HP 33s had only label addressing. With only 26 labels, it was difficult to write programs making use of the entire 30KB of memory.

The memory in the HP 35s is also usable for data storage, in the form of up to 801 numbered memory registers.

Support for vector operations is new in the HP 35s.

Indirect branching, which allows the contents of a memory register to be used as the target of a branching instruction (GTO or XEQ) is available in the HP 33s, but was omitted from the HP 35s.

Design and Manufacture

The HP 35s was designed by Hewlett-Packard in conjunction with Kinpo Electronics, Inc. The latter company manufactures this calculator for HP. The present implementation is mechanically well built and sturdy, with much the same key feel as classic HP calculators[2] and keys that are rated for over a million keypresses.[3]

Programming

Unlike the original HP-35, the HP 35s is keystroke programmable, meaning that it can remember and later execute sequences of keystrokes to solve particular problems of interest to the user. These keystroke programs, in addition to performing any operation normally available on the keyboard, can also make use of conditional and unconditional branching and looping instructions, allowing programs to perform repetitive operations and make decisions.

Even with indirect jumping removed, the HP 35s still supports indirect addressing, with which it is still possible to implement a Universal Turing machine; and therefore the programming model of the HP 35s can be considered Turing complete.

As in normal operation, programming can be done in either in RPN or in D.A.L.

RPN mode programs are usually smaller and faster, while D.A.L. is better suited for interactive use and easier to use for those who are not used to RPN [4].

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Get professional performance from the ultimate RPN scientific programmable calculator. Switch between RPN1 and algebraic entry-system logic at any time. The HP 35s features a two-line display, and the powerful HP Solve2 application.

The HP 35s uses either Reverse Polish Notation (RPN) or Infix notation as input.

Other features of the HP 35s include[1]:

- Two-line alphanumeric LCD display
- 26 memory registers
- Scientific and statistical functions
- Operation in decimal, binary, octal, hexadecimal
- Equation solver (a feature first seen on the HP-34C)
- Numerical integration (also first seen on the HP-34C)
- Support for input and display of fractions
- Complex number and vector calculations
- Unit conversions and table of physical constants
- Approximately 30 kilobytes of memory for programs and/or data

Although the HP 35s has far more functions, processing power, and memory than the original HP-35 which it commemorates, Hewlett-Packard has attempted to give the HP 35s the look of the original HP-35 and other HP calculators of that era. It also features the sloped-front keys for which HP calculators (although not the original HP-35) are well known.

**Programming**

Unlike the original HP-35, the HP 35s is keystroke programmable, meaning that it can remember and later execute sequences of keystrokes to solve particular problems of interest to the user. These keystroke programs, in addition to performing any operation normally available on the keyboard, can also make use of conditional and unconditional branching and looping instructions, allowing programs to perform repetitive operations and make decisions.

Even with indirect jumping removed, the HP 35s still supports indirect addressing, with which it is still possible to implement a Universal Turing machine; and therefore the programming model of the HP 35s can be considered Turing complete.

As in normal operation, programming can be done in either in RPN or in D.A.L.

RPN mode programs are usually smaller and faster, while D.A.L. is better suited for interactive use and easier to use for those who are not used to RPN [4].

Please see Gene Wrights HP 35s review:: http://www.hpcc.org/datafile/V26Special/the35s.pdf