HP-34C
The HP - 34C was the top model of the so-called " thirties " series of calculators by Hewlett -Packard. It was produced from 1979 to 1983 and possessed in addition to a comprehensive facilities with mathematical and scientific functions as the first calculator ever on a numerical root finding and numerical integration. The application manual of the HP -34 contains detailed explanations of the complex functions and various program examples and included two games.
Functions
The search for zeros solved problems of the type. The function to be solved was - possibly after appropriate transformations - defined as a subroutine and had to leave the function value in the display register (X- register). The call was made by inserting two initial values and the SOLVE function (f. ) Followed by the label of the subroutine. Other solutions could be possibly found by new starting values . The algorithm was robust programmed, the manual provided extensive information about the mathematical background and potential problems with "exotic" features.
The even more demanding integration worked similarly. This could be pretend by the choice of display format accuracy; in turn very robust algorithm also provided a - almost always very conservative - estimate of the error of the integral. The manual section for this complex function was even more detailed than the root-finder with 32 pages. This calculation could easily take several minutes.
The store had been significantly expanded and consisted of words per 10 bit ROM and a RAM of 64 registers each 7 bytes from 7168 (7 Ki). Available for the user program were 70 rows and 21 data register ( corresponding to 31 registers), of which an index register I, which allowed an indexed addressing when first turned on. For longer programs, data registers were automatically converted into each 7 lines of code, so that at maximum 210 lines of code were possible. The index register I, then, remained as the single data register; the remaining registers were used by the internal functions and were not accessible to the user. All memory content is retained when you turn and change the battery. The programming includes conditional branching, subroutines with up to 6 levels, expanded comparisons (8 different possible) and stack manipulation, flags, and two usable as a shorthand label " B" keys "A " and (ie, programs with LBL A and LBL B can be personalized with just one press run ). In this model, the keys were four-threaded, with printed on the inclined front Fourth function, as was also already been the case with the HP -67, but it returned to print the Zweit-/Drittfunktion back behind the keys.
The program blocks each took on a complete command, which could consist of up to three keystrokes ( "fully merged keystrokes" ). Internal occupied every such command byte. As this is only 256 different codes are possible, some commands as follows were limited:
- SOLVE and INTEGRATE can be programmed only with the labels 0-3, A or B
- Arithmetic memory is possible only to the memories 0-9 and (i) not storing the I or from .0
- There are only 12 labels ( 0-9, A and B ) are available
- There are only four flags, 0-3.
Comparison
The HP - 34C was in his time competing with the models TI -58 (C) and TI -59, which were significantly cheaper and faster counted, but did not reach the quality of the HP. This applies to the mechanical manufacturing ( in particular, the key ), but also to the numerical robustness. During this time, the question of whether UPN or AOS is the better entry-system logic, discussed intensively.
Internally, the HP- 34C against the HP -41C and its professional standards had to say, which showed next to the shelf ( much longer maturities by power-saving LCD instead of LED display), in particular the flexibility of programming, alphanumerics and extensibility, and only was offset by the even higher price. Also, the precursor to the generation belonging, but sometimes more powerful HP- 67 was sold in parallel with the HP- 34C, also at a significantly higher price. Overall, the HP- 34C was able to maintain its position well until the appearance of the HP -15C.