# NavList:

## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

**Casio fx-115ms calculator usage corrections**

**From:**J Cora

**Date:**2009 Apr 29, 07:32 -0700

I was reviewing my attachment on how to use the casio fx-115MS calculator for sight reduction and found some errors. The calculator runs on solar power or backup battery Though it is not waterproof I think it could be used in a transparent zip bag. It is available for 15 dollars us. You can even do log trig. Degrees can be entered with decimal minutes, decimal minutes and seconds or as degrees, minutes and seconds so it is flexible. Also I just got a casio fx-115ES for 17 dollars us which has a larger display and better editing capabilities and will be working on some doc for it. However the display on the fx-115MS has black lcd text and the newer fx-115ES has blue text which is a bit harder to see. --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To unsubscribe, email NavList-unsubscribe@fer3.com -~----------~----~----~----~------~----~------~--~--- ------------------------------------------------------------- Usage of Casio fx-115MS to calculate Hc and Zc {- minus} the black minus key {x times} the black multiply/times key {% div } the black divide key {SHIFT} the brown SHIFT key at top left {ALPHA} the red alpha key located next to shift {CALC} the grey calc key if SHIFT is pressed first then it is the SOLVE = key or if ALPHA is pressed first then it is the = sign when entering a stored equation {Ans} press the black Ans key this key stops the calculator from recalculating new values so the result of operations can be stored in registers. Notes: When you see something like {ALPHA} A below It means press the {ALPHA} key followed by the {(-)} key. The A is printed above the {(-)} key in red meaning press {ALPHA} first. I chose not to use {ALPHA} {(-)} as it seemed confusing and once the sequence of key presses is understood it goes very quickly. The same goes for {SHIFT} with the second key's text in brown. ------------------------------------------------------------- Altitude sin HC = sin Lat sin decl + cos Lat cos decl cos LHA Format A B C {sin} {ALPHA} A {X times} {sin} {ALPHA} B {+} {cos} {ALPHA} A {X times} {cos} {ALPHA} B {X times} {cos} {ALPHA} C {ALPHA} {CALC} {ALPHA} X {SHIFT} {CALC} A? value in A register press the {=} black key B? value in B register press the {=} black key C? value in C register press the {=} black key X? {SHIFT} {CALC} should display X= sin Hc value {Ans} {SHIFT} STO Y store value in Y {SHIFT} {sin} {ALPHA} Y {=} should display sin-1 Y and Hc value in degrees {SHIFT} STO D store value in D register ------------------------------------------------------------- Azimuth cos angle Z = (sin decl - (sin Lat sin Hc )) / ( cos Lat cos Hc ) Format B A D A D Zc = Z if 180 deg < LHA < 260 deg Zc = 360 - Z if 0 deg < LHA < 180 deg {(} {sin} {ALPHA} B {- minus} {(} {sin} {ALPHA} A {X times} {sin} {ALPHA} D {)} {)} { % div} {(} {cos} {ALPHA} A {X times} {cos} {ALPHA} D {)} {ALPHA} {CALC} {ALPHA} X {SHIFT} {CALC} A? value in A register press the {=} black key B? value in B register press the {=} black key C? value in C register press the {=} black key X? {SHIFT} {CALC} {Ans} {SHIFT} STO Y store value in Y {SHIFT} {cos} {ALPHA} Y {=} should display cos-1 Y and Z value in degrees {SHIFT} STO E store value in E register Zc is calculated from given rules