PC1211, PC1250, etc. TVM

03302021, 04:58 PM
Post: #1




PC1211, PC1250, etc. TVM
In light of all the recent Sharp enthusiasm, here's my attempt at a TVM solver for the PC1211, and compatible models like the PC1250, and no doubt many others (and their corresponding Tandy/Radio Shack versions).
The math is based largely on the 17BII manual's formulas, this TVM program for serveral different HPs, and some of the mathematical notes found here. The PC1211 and PC1250 don't have hyperbolic functions for easy, accurate calculation of e^x1 for x close to zero, but using the infinite series for ln(1+x) does offer some accuracy improvement. Usage is fairly straightforward. On the PC1211, you'll need to switch to DEF mode. On other models like the PC1250, there's a dedicated DEF key that you press instead of Shift. Set B=1 for begin mode, otherwise set B=0. These are the key assignments  for storing variables, first enter the value into the display, then press the appropriate key: Shift Z: Store n Shift X: Store i% Shift C: Store PV Shift V: Store PMT Shift B: Store FV Shift A: Compute n Shift S: Compute i% Shift D: Compute PV Shift F: Compute PMT Shift G: Compute FV Code: 1 "Z":AREAD N Results are generally pretty good, and don't seem to differ by more than a few thousandths of a penny in the few sample problems that I tried. I'm not sure if the Sharps use binary rather than decimal, but I did notice that solving for PMT in a problem where FV=0, then immediately solving for FV could yield small nonzero values on the order of 1E5. 

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Messages In This Thread 
PC1211, PC1250, etc. TVM  Dave Britten  03302021 04:58 PM
RE: PC1211, PC1250, etc. TVM  robve  03302021, 05:07 PM
RE: PC1211, PC1250, etc. TVM  Dave Britten  04012021, 04:44 PM
RE: PC1211, PC1250, etc. TVM  robve  04012021, 05:50 PM
RE: PC1211, PC1250, etc. TVM  robve  Yesterday, 09:17 PM

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