HP-48 series
HP -48 is the designation of a series programmable calculator of the U.S. manufacturer Hewlett -Packard (HP).
The HP - 48SX was introduced in 1989 and is distinguished by a new programming concept called RPL from which was first introduced in 1987 in the HP- 28C and HP- 28S. As a new top model in the calculator program Hewlett- Packard HP - 48SX replaced the HP -41 from, who had been brought as HP -41C in 1979 to the market.
Functions
Unlike its predecessor, the programming differed in the following respects:
- The stack was no longer limited to four levels, but could grow arbitrarily. This allowed programs to run as a true sub- programs without existing stack contents were destroyed.
- The data storage was handled could no longer register ( on STO xx commands ), but so also excluded here on global and local variables from influencing different programs are
- The RPL programming language is characterized by complex control structures, such as are known from the higher programming languages here, but also here the concept of reverse Polish notation (RPN ) was transferred ( see example RPL)
- Variables in addition to the usual types, complex numbers, matrices and vectors, algebraic expressions, lists or programs are assigned
- Scalars can ( umrechenbaren and possibly assembled of several parts, for example, or ) be linked units
- Recursive programming, and algebraic expressions, arbitrary nesting
- Consistent interpretation of any mathematical functions also to the handling of complex numbers and of real / complex matrices (where mathematically defined )
- Manipulation of algebraic expressions through to the formal discharge of functions
- Infrared communication between two HP-48 connector for serial RS-232 interface
The first versions had a relatively small memory of 32 KB of RAM, which could be extended by a maximum of two memory cards (initially proprietary HP format because memory cards were not at market conditions at that time, but now switched to the HP - 49G SD card ). For many applications, this was initially sufficient because RPL is processed by an interpreter and no space for the compiled file is needed.
Because of these capabilities, the HP- 48SX a milestone in the development of the calculator represent, but gained no more the awareness and importance in practice by the competition of PC-based applications (such as Lotus 123, Microsoft Excel, Quattro Pro) as the predecessor HP -41 was still possible.
Unlike many PC spreadsheets, the HP -48 does not deviate to the binary arithmetic of mathematical coprocessor ( at the time of conception in 1989, these were in the PC Intel coprocessors 80287 and 80387 ), but rather converted into BCD. This principle allows a high numerical accuracy. Since the HP -48 and, however, expect his successor with 15 digits internally and round each intermediate result to 12 digits, which (without tampering with the operating system) actually usable numerical accuracy is considerably less than twice the accuracy of conventional PC processors (about 16 digits ). In addition, the operating system is characterized by absolute stability. Procedures ( exploits ) for system crashes or internal system error messages are not known. With the release of the HP 48SX J operating system and the last known error in the algorithms have been eliminated. ( Firmware images can be obtained free of charge since 2000. These firmware images are also used by many PC - based HP -48 emulators required.)
The clocked with a maximum of 4 MHz processor, codenamed Saturn is a development of HP. The operating system includes about 256 KB for the HP 48SX, 512 KB for the HP 48GX and about 1 MB in the computers of 49G/49G / 50G series.
Specifications
1) temperature-dependent 2) HP- specific infrared interface
Successor
HP- 49G
Immediate HP -48 's successor, the 49G series, mainly through an expansion of the HP -48 instruction set, a powerful computer algebra system (CAS ) for symbolic mathematical operations and a slightly improved performance of the hardware, but also by a poor quality processed keyboard excel. The HP - 49G is also a large part of the software has become much faster by optimizing. In this case, the software was translated into assembly language. The HP - 49G and the infrared interface has been omitted - it was, however, reintroduced with the successor model HP 49g .
This calculator model is the last of its kind with Saturn processor.
HP- 49g
The infrared interface was re- installed in the successor model HP 49g , but it uses the IrCOMM protocol and not like the HP -48 series a HP- specific protocol. The HP 49g has instead of a serial port a USB port, which allows for faster data exchange with the PC (for Microsoft Windows, a driver on CD- ROM is included with the Linux kernel 2.6.x has a corresponding driver). Since the HP- 49g an ARM processor with 75 MHz is used on the Saturn processor is emulated by software. Production of the Saturn CPUs had been set by NEC.
The firmware of the HP 49g can not be used on the various HP -48 emulators such as the Emu48 due to the Saturn emulator in the calculator. In early 2007 there were no HP emulators for PCs available that could emulate directly on the ROM image of the firmware the ARM -based architecture of the HP 49g .
HP- 50g
The HP 50g is the latest model of 48/49/50-Reihe HP and has the capabilities of the HP 49g is equipped with an improved keyboard and expanded through a serial interface. The HP - 50g used as a further innovation four micro batteries ( AAA batteries). This model includes the color scheme of the HP -48 series. The housing is black by default. The shift keys have the colors white and orange, the alpha key is like the HP 49g yellow. The HP -50G is also available with blue housing.
The well-known by the HP -48 Extensions for Physics (hundreds of formulas with equation solver ) and Chemistry ( periodic table, properties of all chemical elements ) are available as libraries for the HP - 50g is available free of charge.
The newer firmware for the HP- 50g can be used directly without changes in HP- 49g calculators, which users of the previous model to benefit all functional improvements. For the current model, software is available, with which the entire user guide for all the programs installed in the computer is at German, further is also the equation library in German available.