Sinclair Scientific question

09012015, 01:44 PM
Post: #1




Sinclair Scientific question
Are there Sinclair Scientific owners here? I had created this emulator based on a software version and one of my kit builders had a question on the accuracy.
<quote> But someting strange in happening : I put it in the sinclair mode and calculate here sin of 25 and the result wos 1,5720 Ex.00 (the same as on the online one, that you sended me), but the father Google said that it is  0,1323. I know that the sinclair is well known for itÂ´s inacuracy, but the minus seems little bit much... So, is this good resault on the sinclair ? Or I mess something more up? (I have tested the LED on different example 19 999 999 9 and I ensure that the LED work fine on the negative resault.) </quote> So I checked the web emulator and my hardware emulator and both got result of 2.4797 E 1 (google gives 0.13235... on SIN(25 radian)). I want to know how should I make out of this (I am dumb on math). If someone has a working Sinclair Scientific, can he / she make a run and see if my emulator is working properly? C, 2, 5, E, 1, sin (as in ^, +) And if they agree, what would be the impact of someone using this calculator for real work. (It was advertised as a calculator back then, not a toy) Thanks. 

09012015, 03:54 PM
(This post was last modified: 09012015 04:18 PM by EdS2.)
Post: #2




RE: Sinclair Scientific question
According to the manual, the input range for sin() is from 0 to pi/2  so 25 radians is out of range.
http://www.datamath.net/Manuals_Others/S...fic_GB.pdf But the accuracy is about as good as a slide rule, maybe a little better, so long as you stay within the allowed ranges  and as such, could be a useful calculator for some purposes. You'll almost certainly need pencil and paper to store intermediate results. I get the same result with my Sinclair: If you do your own range reduction  enter pi, multiply by 8, subtract 25  then you can take the sin, and you'll get 1.3218E01 which is pretty close to correct. (It's not possible, I think, to postmultiply by a negative number, so you'll have to take account of the sign yourself.) 

09022015, 04:50 PM
Post: #3




RE: Sinclair Scientific question
thanks EdS, I should have read the manual throughout.


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