Monday, June 27, 2022

Retro Review: Texas Instruments BA-Solar

Retro Review: Texas Instruments BA-Solar








Finance + Solar + 1980s


Quick Facts


Model:  BA-Solar

Company:  Texas Instruments

Years:  1986 - 1990s; a refresh , BA-35 SOLAR was produced 1996-2000s

Type:  Finance

Batteries: Solar 

Operating Modes:  Chain

Number of Registers: 1, |MEM|

Display:  1 line, 10 digits


Features


The [ MODE ] key is used to toggle between three modes:


FIN Mode:  Time Value of Money  (FIN indicator)


N:  number of payments

%i:  periodic interest rate

PV:  present value

PMT:  payment

FV:  future value


The current cash flow convention is not used, instead the following equation is (I think) used in solving time value of money calculations: 


PV = FV *  SPPV + PMT * USPV

SPPV = single present value factor

USPV = present value annuity factor


We also have amortization functions:


BAL:  balance after any payment

I/P:  interest and principal at any payment

payment_1 P1/P2 payment_2 I/P:  cumulative interest and principal


There are ×12 and ÷12 aids, but we still have to press [ N ] and [ %i ] to register the values, they are not automatic.  


STAT Mode:  Statistics  (STAT indicator)


The BA-SOLAR (and the later BA-35 SOLAR) has both single variable statistics and linear regression.


In linear regression, use the [x<>y] key to change between x and y.   The key will also be used to switch between results.  


Prediction values can be calculated with x' and y'.


The equation used for linear regression is y = a*x + b,  a = slope, b = intercept.


Profit Mode (no indicator)


The profit mode makes the following solver available:


CST:  cost

SEL:  sell

MAR:  margin

MU:  markup


Functions Available in All Modes


Percent Calculations (%):

Add %:  x [ + ] y [ % ] [ = ]

Subtract %:  x [ - ] y [ % ] [ = ]

Multiply %:  x [ × ] y [ % ] [ = ]

Percent Ratio:  part [ ÷ ] whole [ % ] [ = ]

Percent Change:  new [ 2nd ] ( ⊿% ) old [ = ]


rate >EFF payments/year:  convert to effective rate

rate >APR payments/year:  convert to APR/nominal rate


Mathematics:

Natural logarithm and antilogarithm:  ln x, ^x

Square and square root

Power

Reciprocal


Final Thoughts


This is a great basic financial calculator.  I have both the BA-SOLAR and BA-35 SOLAR.   To be honest, I like the keyboard of the original BA-SOLAR better, the keys feel a bit more solid and responsive.  Even though they are no longer in production, the BA-SOLAR is still reasonably available on sites such as eBay and other online stores.  


Source:


Woerner, Joerg.  "Texas Instruments BA-SOLAR"  Last Updated December 5, 2001.   http://www.datamath.org/Sci/Modern/BA-SOLAR.htm   Retrieved May 19, 2022.


Eddie


All original content copyright, © 2011-2022.  Edward Shore.   Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited.  This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author. 


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