APF Mark 90
Brief History
The most sophisticated scientific calculators in APF's uniformized product range were manufactured in Japan from 1977: both programmable and standard versions were made from the MOS chipset used in the Commodore PR100. Accordingly, the Mark 56 model contains one row less keys than the full-fledged Mark 90. Several labels on keys have been changed from the original Commodore’s one to match other APF models. As with the original Commodore machines, the leakage of the batteries under the display made the display unusable, as can be seen in the pictures.
Interesting, that both the original Commodore version and both APF variants were assembled in Hungary: after the stock of Híradástechnika Szövetkezet (Telecommunication Cooperative) of the highly successful PTK-1072 (the locally assembled version of the PR100) ran out, they also bought the remaining stocks of the APF machines: the Mark 56 has renamed to TK-1072-1, and Mark 90 to PTK-1072-1.
| Manufacturer: | APF Electronics, Inc. (USA/Japan) |
| Mfg. date: | 1977 |
| Size: | 7,8×15,2×3 cm |
| Weight (ready for operate): | n.a. |
| Type: | programmable scientific |
| Capacity: | 8/8+2 digits (input/display) 9/9+2 digits (internal precision) |
| Operating logic: | algebraic |
| CPU: | MOS MPS7530 201 |
| Registers: | 2 standard (with saving the pending operation) 1 constant (with saving the pending operation) 4 bracket (with saving the pending operation) 10 memory (with aritmetic) |
| Features: | %calculation with percent +/-change sign (direct entry of negative numbers) RVexchange registers (X-Y) Ffloating-point notation Fixfixed-point notation: the listed decimals can be chosen (0-7) Sciscientific (exponential) notation Engengineering notation Sqrsquare root x2square pivalue of pi (3.1415..) can be recalled 1/xreciprocal trigtrigonometrical functions (sin, cos, tan and inverses: arcsin, arccos, arctan) hyphyperbolic functions (sinh, cosh, tanh and inverses: ar sinh, ar cosh, ar tanh) DMS-DDconversion of decimal and sexagesimal numbers logexponential and logarithmical functions (10- and e-base) yxraising to power SDone variable statistics: calculating mean and standard deviation LRtwo-variable statistics: linear regression nCrprobability calculations P-Rconverting coordinates between rectangular and polar systems n!factorial |
| Display: | 8+2+2 digit LED (HP) |
| Power: | 3×AA NiCd battery (built-in) |
| Programming method: | keystroke-programmable |
| Program capacity: | 72 keystrokes |
| Test results: | trigonometry:result of sin-1(cos-1(tan-1(tan(cos(sin(60°)))))), reference value: 60. 60.08726889 exponential:result of 0.999160000, reference value (first 14 digits): 3.0068804206375×10-70 3.006559827E-70 |
Mark 90
Inside of the Mark 90
Keyboard of the Mark 90
Similar items
