The smallest ever LED RPN calculator  Printable Version + HP Forums (https://archived.hpcalc.org/museumforum) + Forum: HP Museum Forums (https://archived.hpcalc.org/museumforum/forum1.html) + Forum: Old HP Forum Archives (https://archived.hpcalc.org/museumforum/forum2.html) + Thread: The smallest ever LED RPN calculator (/thread211399.html) 
The smallest ever LED RPN calculator  Michael de Estrada  02122012 And it's not an HP
About the size of a pack of cigarettes, the Hanimex 276, made in Hong Kong for the Australian Hanimex Company was the smallest ever LED RPN calculator. It was based on the National Semiconductor MM5760 chipset with a calculator forensics number of 8.843762. It sports most of the same functions of the Novus Mathematician except for x^2 and M + x^2, due to the reduced number of keyboard buttons. This particular pristine unit currently resides in the collection of one out our beloved members, who is well know for his addiction to nonHP RPN calculators.
Edited: 12 Feb 2012, 7:25 p.m.
Re: The smallest ever LED RPN calculator  Martin Pinckney  02122012 About the same feature set as the HP 35, and IMO very attractive styling, too.
When was it produced?
Re: The smallest ever LED RPN calculator  Michael de Estrada  02122012 I can't say for certain, but mid to late 1970s when National Semiconductor was making the chips. There's a whole bunch of other brands that used them, including the Argentinian Microcifra 10 and Taiwanese Prinztronic. Two big differences from the HP35 is that it only has a 3level stack and no scientific notation. Edited: 12 Feb 2012, 10:51 p.m.
Re: The smallest ever LED RPN calculator  Paul Dale  02122012 This looks remarkably similar to some of the scientific 4banger designs that have floated around over the years.
 Pauli
Re: The smallest ever LED RPN calculator  David Griffith  02132012 I wonder how much it would cost to produce something like that nowadays.
Re: The smallest ever LED RPN calculator  hpnut  02132012 i wonder of Michael Steinmann can replicate an LED HP25C :)
Re: Smallest?  Maximilian Hohmann  02132012 Good morning! I don't have that particular calculator (alas...) to take masurements, but if it's the same size than the similar looking Hanimex 202, then the Sinclair Scientific is smaller. In width, thickness, area and volume, but not in length. If that counts. Funny contest. Usually it goes: Mine is bigger :) !
Regards, Re: Smallest?  Michael de Estrada  02132012 You are correct ! I had completely forgotten about the Sinclair Scientific. The dimensions I measured using a ruler are as follows: Hanimex 276 : 37/8" L X 21/2" W X 7/8" T Sinclair Scientific : 43/8" L X 2" W X 3/4" T That works out to the following areas and volumes: Hanimex 276 : A = 9.7 in^2 V = 8.5 in^3 Sinclair Scientific : A = 8.8 in^2 V = 6.6 in^3 Also, the Sinclair is 9 grams lighter at 105gm with 4 AAA cells .vs. 114gm for the Hanimex with a 9V battery. So, I probably should have made the title "the second smallest ever RPN LED calculator."
The Sinclair was far more limited with only a two level stack and no storage memory, although it could handle much larger numbers due its perpetual scientific notation mode. Also, it performs trig operations in radians only and lacks the constant pi for easy conversion from or to degrees. Log operations are base 10 as well. Edited: 13 Feb 2012, 10:59 a.m.
Re: The smallest ever LED RPN calculator  Raymond Del Tondo  02132012 Hi Michael, is it smaller than a Commodore Minuteman 6* ? Cheers
Raymond
Re: The smallest ever LED RPN calculator  Michael de Estrada  02132012 It's about the same size.
Re: The smallest ever LED RPN calculator  John Robinson  02142012 My first ever calculator, well actually my fathers calculator was a Hanimex ESR 1010SN, see : Hanimex ESR1010SN
Cheers, Re: The smallest ever LED RPN calculator  Bill Wiese  02162012 This was a variation on my/my dad's 2nd calculator externals.
The package design & form factor look remarkably like that of the 1975vintage Casio "Pocket Mini"... in particular The std Pocket Mini used a bluegreen 8 digit VFD display, as did most Casio calcs of those years. The Pocket Mini came in a couple of revisions... including a LED version with rounder keys. The common VFD version had roundedcorner square keys pulled into a 'tighter matrix' (i.e, matrix has more substantial border from edge of calc) and had gasketing around the keys. Casio VFD 4bangers at the time used Hitachi calc chips. http://images.search.yahoo.com/search/images?_adv_prop=image&fr=yfpt465&va=casio+pocket+mini
Edited: 16 Feb 2012, 10:27 p.m.
