Programming Exercise (HP-15C, 15C LE - and others)

[bkn42]

(03-30-2014 03:51 AM)Gerson W. Barbosa Wrote:  At first I thought you had converted the pi program to the "HP-55" like the previous one for the ln(2) series, judging by the picture in your detailed thread on the "HP-55", but then I realized it was the rational approximation 355/113. This one appears in the small HP-35 manual, BTW.

Its when I started my HP Calculator FPGA project, I first saw the 355/113 approximation for PI in the HP-35 manual. I used it as a first test of my FPGA design.

On a side note, since there is a lot of execution times being posted here, I tried turning up the internal clock rate of my "HP-55". I never designed it for speed just to be functionally equivalent to the classic HPs. However, I was able to get my current design to run at 84MHz (a 3x increase) -- this is not too bad for the FPGA I'm using. Anyway, all the execution times I posted are now one third of what I stated.

Brian