Comparison
 Híradástechnika K-831 (2. változat) |  Híradástechnika TI-57 II | |
| Manufacturer: | Híradástechnika Szövetkezet (Hungary) | Híradástechnika Szövetkezet (Hungary) |
| OEM: | Bowmar-Ali Inc. (USA) | Texas Instruments (USA) |
| OEM model: | MX-50 | TI-57-II |
| Mfg. date: | 1973 | 1985 |
| Size: | 7,7×14,8×3,3 cm | 7,4×14,7×2,2 cm |
| Weight (ready for operate): | 190 g | 90 g |
| Price: | HUF 9.000 (HT, MIGÉRT, 1974) | |
| Type: | four-function | programmable scientific |
| Capacity: | 8 digits (input/display) 8 digits (internal precision) | 8/8+2 digits (input/display) 11/11+2 digits (internal precision) |
| Operating logic: | semi-arithmetic (Rockwell) | AOS |
| CPU: | Rockwell 15332PC | Texas Instruments CD4572BN2 + CD4555BNL |
| Registers: | 2 standard (with saving the pending operation) 1 constant (with saving the pending operation) | 3 standard (with saving the pending operation) 15 bracket maximum of 7 memory (with aritmetic) |
| Features: | %calculation with percent Ffloating-point notation | +/-change sign (direct entry of negative numbers) Ffloating-point notation Fixfixed-point notation: the listed decimals can be chosen (0-7) Sciscientific (exponential) notation Sqrsquare root x2square pivalue of pi (3.1415..) can be recalled 1/xreciprocal trigtrigonometrical functions (sin, cos, tan and inverses: arcsin, arccos, arctan) DMS-DDconversion of decimal and sexagesimal numbers logexponential and logarithmical functions (10- and e-base) yxraising to power P-Rconverting coordinates between rectangular and polar systems n!factorial |
| Display: | 8+1 digit LED (Bowmar Optostic) | 8+2+2 digit LCD |
| Power: | 3×AA NiCd rechargeable battery (built-in) with E-69 charger | 2×LR44 |
| Programming method: | merged keystroke-programmable | |
| Program capacity: | maximum of 48 steps | |
| Test results: | trigonometry:result of sin-1(cos-1(tan-1(tan(cos(sin(60°)))))), reference value: 60. 60.019845215 exponential:result of 0.999160000, reference value (first 14 digits): 3.0068804206375×10-70 3.006920635E-70 |