# HP-10C series

The HP -10C series calculators were brought by Hewlett -Packard in 1981 as a successor to the " thirties " series on the market and belong to the Voyager series. This series includes the models HP- 10C to HP -16C, all of which have a similar appearance as of elongated flat block; only with the HP -12C, the metallic shell is gold rather than silver. The LC display is ten digits. First time at HP computers button cells ( three pieces of type LR 44 ) are used for the power supply. All models are programmable, but extensions, opportunities for exchange programs with identical computers or printer port were not provided.

As an input method, use the calculator Reverse Polish Notation (RPN ).

## Models

The HP- 10C series includes five models ( with the year of its production ):

- HP- 10C - Mathematics and scientific calculator; Base model (1982-1984)
- HP- 11C - Mathematics and scientific calculator; medium requirements (1981-1989)
- HP -12C - Financial Math calculator (1981 -present)
- HP -15C - Mathematics and scientific calculator; high demands (1982-1989)
- HP -16C - Calculator for computer programmers ( 1982-1989 )

The models HP- 11C and HP -12C were presented as the first members on 1 September 1981 HP -15C and HP -16C was followed on 1 July 1982 and the HP- 10C, two months later, on September 3, 1982. During the series with updated interior - - in 1989 largely ended, the HP -12C is still available.

## The HP -10C

The HP -10C was used as a base model for simple mathematical and scientific problems, and in this series the model with the smallest equipment. The HP -11C constituted the largest internal competition with the HP- 10C, as he for a relatively small fee ( the HP -10C cost U.S. $ 80 ) with about twice the scope offered. Therefore poor sales figures bestowed the HP- 10C is a short residence time at the market, in 1984 the production was stopped. It is therefore certainly the rarest model of this series.

## The HP -12C

The HP -12C is a common, programmable financial calculator. It can be used in addition to extensive basic functions of many other standard calculations - even iterative way - financial mathematics perform: Internal rate of return, annuities, present value and end value, and payback calculations. In 2003, the HP- 12C Platinum came in addition to the market, which has some additional features and a revised design ( platinum color ). The 12C is produced externally and functionally unchanged for 30 years, what is likely to be unique for a unit of information technology, especially for a calculator.

## The HP - 11C and HP -15C

The HP -11C is a mathematical and scientific calculator for average requirements. With respect to the HP- 10C are hyperbolic functions, a pseudo - random number generator and probability calculation functions for the added, the memory is twice as large. For programming, there are 15 labels, 8 comparison operations (instead of just 2 like the HP -10C), subroutines ( 4 levels ), indexed addressing, and two flags available. The memory consists of 30 registers each 7-byte, one of which is dedicated to said index register I; the remaining registers allow up to 203 program steps, or up to 20 data storage at 63 program steps into links automatically. The HP -11C in 1981 cost 135 U.S. $, U.S. $ 1989 or 56.

The HP -15C was considered a high-end calculator, in addition to the HP- 11C, it offers zeros determination, numerical integration, calculating with complex numbers and extensive matrix functions. He was the successor of the HP- 34C and extended its capabilities considerably again.

The storage area - opposite the 11C again about doubled - can be spread on data and program memory and is managed dynamically. A complete novelty were the matrix functions for up to five matrices, which were all embedded in the elegant UPN logic. Complex number calculations are accurate by a second stack as possible with real numbers, with exactly the same use of all four stack registers. When introduced in the HP -15C cost $ 135. Because of its high efficiency of the 15C is a very popular and used unit now generates prices that are in magnitude over the then replacement value. 2011 externally and functionally identical, but equipped with a new interior successor of Hewlett Packard in the U.S. market was sold as a "Limited Edition".

## The HP -16C

The HP - 16C is the first and only calculator designed for programmers ( eg, shift and rotate functions, adjustable word length and complement representation, etc.) It enabled the displaying and converting the various number systems are (DEC -BIN -HEX -OCT ) and logical combinations and was particularly advocate understand assembler close calculation steps.

When introduced in the HP -16C cost 150 U.S. $, which were later reduced to U.S. $ 120.

A competitor of HP, Casio, presented a similar model (CM -100), which was equipped with most of the same features as the HP -16C. He had no battery and is driven by a solar cell.

## Technology

The " Voyager " computers were developed with the aim, inter alia, low energy consumption. Thus, the leakage currents of the CMOS circuits used were reduced to the technically possible. Goal of the designers was to work three to six months with a battery pack: In practice, the computer usually reached several years with one set of batteries, the devices have no mechanical interruption of the circuit.

## Internal structure

The organization of the memory register as a result of the a CPU with an internal 56 -bit registers, a variant of the CPU of the HP -41. This word length was due to the space required for ten digits in BCD representation (4 bits each ), two digits for the exponent, and the two sign of mantissa and exponent, the 4 to assign each bit also. At the machine level, individual bits, agencies, groups of figures suggest (eg the complete mantissa ) or bytes - for the interpretation as program instructions - appeal. The memory is addressed serially. For the ROM is in conformance with this concept from one word addressing with 10 bit lengths.

## Arithmetic

One of the lesser known features of this series is the quality of the built-in, based as it did in previous models to BCD arithmetic. Hewlett -Packard could win this William Kahan of UC Berkeley, the architect of the IEEE 754 standard for floating-point arithmetic to design the numerical algorithms. He also wrote parts of the operating instructions.

## Programming

The computers of the series are programmable keys, that is, a series of keystrokes is saved and can be recalled later. For program branches are conditional branches, loop control commands and several (up to seven ) sub-program levels. An alphanumeric display but there is not, so a key or key sequence is still represented by digits, such as 42.21.14 for " LBL D" on an HP -15C.

The individual functions vary as follows:

## Evaluation and development

The " Voyager " computer stand out, especially when compared to their previous generation, by high manufacturing quality and are often also at the age of almost 30 years, still in use. Although the technology is outdated, the displays of these machines obtain better contrast than modern matrix displays. Used series units are in high demand, so as to achieve the HP -11C and HP -15C regularly used prices well above the original price of today's calculators. In addition, there are numerous emulator programs for different operating systems, including for smartphones.

However, experience in particular with the functionality of the HP- 15C and the comparison with the HP -41 also showed that the concept of keys programmable computer was maxed out with only a numeric display. Therefore, the development led in the second half of the 1980s to an object-oriented, high level programming language ( RPL) and the estimates based on computers HP- 28C / S, HP- 48 and its successors.