4 ms·
Fun little memory, as a kid I've been "hacking" on an Elektronika calculator as well, if you can call it that. On an Elektronika MK-18M I accidentally found tha
by cuu508 10y ago
Fun little memory, as a kid I've been "hacking" on an Elektronika calculator as well, if you can call it that. On an Elektronika MK-18M I accidentally found that one of the scientific functions takes a noticeable amount of time to compute. The calculator would freeze for good 100ms until the answer comes back. And the interesting thing was, the processing time depended on the value I used for the function. By using what I now know is called bisection method, I found a value that choked up the calculator for good 3 seconds. This is not a hack of course but I felt like I had found a small clue about how the function is implemented in the calculator.
- userbinator 10y agoIt probably uses CORDIC: https://en.wikipedia.org/wiki/CORDIC https://en.wikipedia.org/wiki/CORDIC That also reminds me of the note on this page about the Sinclair Scientific calculator's speed: http://files.righto.com/calculator/sinclair_scientific_simulator.html http://files.righto.com/calculator/sinclair_scientific_simul... Due to the simple loop-based algorithms, the speed of the Sinclair Scientific calculator varies from good to horribly slow depending on the values. For instance, sin .1 takes under a second, but sin 1 takes about 7.5 seconds. Arccos .2 takes about 15 seconds. Log and antilog have the overhead of recomputing the constant 229.15, and take about 1 to 2 seconds. It's worth noting that modern low-end calculators still use very simple processors operating in the kHz range, because they're cheap, ultra-low-power, and sufficiently fast. This does occasionally manifest itself in taking a second or two for computing some more complex functions.