$1 scientific calculator 03-21-2019, 03:05 AM Post: #1 Rick314 Junior Member Posts: 33 Joined: Oct 2014$1 scientific calculator
I got my first $1 scientific calculator from a local Dollar Tree Store in 2009. A 2011 closed HP Forum thread discusses it, and it is very impressive for the price. I thought these notes I compiled about it might be useful to others. Code: * Look carefully for the dark red key legends, used only in special calculator modes: A B C D E F for HEX mode entry. n <mean> <s> DATA for STAT mode entry (DATA) and results. * Complex example 1+j2 * 4+j8 = -12+j16: CPLX 1 a 2 b X 4 a 8 b = (-12) b (16). Only + - * / are available, not exp, log, trig, sqrt, etc. * Polar <-> Rectangular example: 3 a 4 b ->r<theta> (5) b (53.1 deg) ->xy (3) b (4). * Statistics example: STAT 3 DATA 2 DATA 1 DATA n (3) <avg> (2) s (1) <sum_x> (6) <sum_x^2> (14) <sigma> 0.816. Clear last entry by CD. Clear all by STAT (exit the mode). * Working Register (x <-> y) example: 3 / 6 <up/down arrow = 2nd ( keys> = (2, 6/3 instead of 3/6). * Working Register ("constants") example: 2 * = (4) = (8) = (16) = (32) / 2 = (16) = (8) = (4) ... * HEX mode appears to be 40 bit 2's comp ("0 - 1 =" shows FFFFFFFFFF) but it isn't 40 bits. HEX Mode arithmetic is limited to +/- 1e10-1 (10 decimal digits) -- Do this: 9999999999 (10 9s) HEX (= 2540bE3FF) +/- (= FdAbF41C01), good. "- 1 =" shows "E" error. Guess: HEX is converted to DEC, 10-digit integer math done, then back to HEX. log2(2e10) = 34.2 bits. So the HEX is limited to 34-bit 2s complement operations, ~= +/- 2^33 ~= +/- 8.6e9. * BIN mode seems to be limited to 10-bit 2s complement (-512 to +511 decimal). BIN 111111111 (9 1s) can +/- OK, but adding 1 to it results in Error (overflow). Similarly, 1000000000 (-512 decimal) - 1 = Error. * Base Conversion Ranges Binary 1000000000 to 0111111111 (10-bit 2s comp, -512 to 511) Octal 4000000000 to 3777777777 (10-digit 2s comp octal) Decimal -9999999999 to 9999999999 (+/- 10 digits) Hex FdAbF41C01 to 02540bE3ff (same as the Decimal range) * Display mode: TAB 0-9 (# of decimal places), TAB . (default general display), F<->E (floating point vs exponential toggle, only applies to the range 1e-9 to 1e10-1). * An extra digit is kept in addition to the 10 displayed. 1 + 1e-10 = (1) - 1 = (1e-10). Doing the same with 1e-11 doesn't work. * Application: 1 + 1e-10 = x^2 x^2 x^2... (41 times) ~= 3.2e95 and is still in range. This is x^(2^41). 1 + 1e-10 = y^x (2 y^x 41) = (the same result).  « Next Oldest | Next Newest »  Messages In This Thread$1 scientific calculator - Rick314 - 03-21-2019 03:05 AM RE: $1 scientific calculator - Steve Simpkin - 03-21-2019, 06:21 AM RE:$1 scientific calculator - grsbanks - 03-21-2019, 07:03 AM RE: $1 scientific calculator - Dave Britten - 01-18-2020, 12:49 AM RE:$1 scientific calculator - toml_12953 - 03-21-2019, 07:30 AM RE: $1 scientific calculator - Rick314 - 01-17-2020, 10:49 PM RE:$1 scientific calculator - Eddie W. Shore - 03-21-2019, 12:59 PM

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