Thursday, July 31, 2014

Sharp EL-501X (today) vs TI-35 Plus (1989)

TI-35 Plus Notes vs Sharp EL-501X (and almost all of its clones)

Ever wanted a TI-35 Plus? First you could go to eBay or other online stores and try to hunt one down or invest up to $10 for one of the many close-version that are still manufactured and sold today. There is even a version sold at the Dollar Store! (The keyboard of that $1 Store I bought is crappy.) Today I will be comparing the Sharp EL-501X against the 1989 TI-35 Plus (and its solar sister, TI-36 Solar (no X)).

Since I never actually owned a TI-35 Plus, all the information will be from its manual. I did buy a TI-36 Solar guidebook, 20 years ago or so, from a clearance bin at Toys R Us of all places. The Sharp EL-501X I bought this week primarily for this blog entry, and to replace a blue cased EL-501X I gave to my cousin's daughter.

Source of the TI-35 Plus information:

TI-35 Plus Page:

Side plug: Datamath is an excellent web page for all things Texas Instruments calculators, past and preset.


Internal Digits: 12

Complex Mode
Base Display Modes: Binary, Decimal, Octal, Hexadecimal
One Variable Statistics

Complex Mode is limited to arithmetic. The real part is stored and recalled using the [ a ] key and the [ b ] key is for the imaginary part. ( a + bi )

Base Display Modes (except for Decimal) is limited to arithmetic. To convert numbers, just call their respective mode.

Number of memory registers: 1

Factorial Function: n!. Only takes positive integers or zero unless an error occurs.

Polar/Rectangular Conversions:
[ a ] is used for x and r
[ b ] is used for y and θ

Basic Scientific Function set: hyperbolic functions, trigonometric functions and inverses, exponential functions and inverses, reciprocal, square root, cube root, power, arithmetic, π, 3-decimal random number (usually labeled RND)


TI-35 Plus: 10 digits plus 2 digit exponent
EL-501X:10 digits or 8 digit plus 2 digit exponent

Exchange Key:
TI-35 Plus has two: EXC to change the number in the display with the number in the memory register. x<>y exchanges operands in power, root, division, and subtraction calculations.
EL-501X: Only the latter is present, often symbolized by a vertical line with up and down arrows. ( [2ndF] [ ( ] )

Decimal Display Settings:
TI-35 Plus: Four permanent modes: floating, fixed, scientific, engineering
EL-501X: Two permanent modes: floating and fixed. Numbers can be toggled between floating/fixed and scientific notation by pressing [ F ←→ E ]

Things the TI-35 Plus had that the EL-501X and most of the clones do not:

Permutations and Combinations. The TI-35 Plus facilitated the use of the [ a ] and [ b ] keys.

Normal Cumulative Distribution Functions (mean = 0, variance = 1, given z):
R(z): area between 0 and z
Q(z): area from z to positive infinity (upper tail)
P(z): area from negative infinity to z (lower tail)

In more advanced calculators and mathematical software, the normalcdf function calculates P(z) (lower tail).

One variate of the EL-501X, the Canon F-604 has permutations, combinations, memory exchange, and fractions. Unfortunately the one I bought not to long ago, the zero key reseted the calculator, so I had to return it. Hopefully it is not the case with all F-604s.

Yes - entry level scientific calculators still exist in the market.

Take care everyone, thanks for comments and questions. Much appreciated. Eddie

This blog is property of Edward Shore. 2014


Swiss Micros DM16L: Advanced Boolean and Factorial (up to 20)

Swiss Micros DM16L:   Advanced Boolean and Factorial (up to 20) Introduction The program listing, for the Swiss Micros DM16L and Hewlett Pac...