Retro Review: Radio Shack EC-2024

Retro Review:  Radio Shack EC-2024

Quick Facts

Company:  Radio Shack
Years in Production: Around 1994
Original Price: $24.99
Battery:  Solar with Battery backup  (RS 389A)
Type:  Desktop- Fold-able
Number of Digits: 10

Initial cost and year came from the CALCUSUEM web site:  http://www.calcuseum.com/SCRAPBOOK/BONUS/46394/1.htm  (retrieved August 4, 2019)

I paid $3 for this at a swap meet. 

Keyboard

The some of the keys are larger than the others.  The plus key has an L-shape, while the minus key is large, and the equals key, labeled the "ANSWER BAR".

The keyboard is alright.  If you type at a reasonable pace, the keys are responsive.  If you are speed typist, prepare to be disappointed. 

The EC-2024 works best when the calculator is under full light. 

Settings 

There are two settings switches:

Rounding:  always round up, always round down, or 5/4 (use the general rounding rules)

Decimal Setting:  float, 0 decimal places, 2 decimal places, 3 decimal places, or add mode.  In add mode, every number that is added or subtracted is automatically divided by 100.  This allows for rapid entry of dollars and cents without having to enter the decimal point. 

The Δ% Key

How the percent key [ Δ% ] depends on what arithmetic operation is used with it.

x [ + ] y [ Δ%] returns (x + y)/y * 100%

Example:  250 [ + ] 300 [ Δ% ] returns 183.3333333

x [ - ] y [ Δ% ] returns (x - y)/y * 100%

Example:  250 [ - ] 300 [ Δ% ] returns -16.66666666

(This is the true percent change function, x is new, y is old)

x [ * ] y [ Δ% ] returns x + x * y / 100

Example:  250 [ * ] 300 [ Δ% ] returns 1000

x [ ÷ ] y [ Δ% ] returns x/(1 - y/100)

Example:  250 [ ÷ ] 300 [ Δ% ] returns -125

Verdict

It's a nice calculator and will fulfill the basic needs.  The keyboard is nice and fold-able.  If you get it, spending a few dollars (like no more than $5) is good. 

Eddie

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Retro Review: Sharp Compet CS-2302 Review

Retro Review:  Sharp Compet CS-2302 Review

I’m going for a little departure from the usual types of calculators I cover.

Sharp Compet CS-2302

Company:  Sharp

Type:  Adding Machine, Paperless

Years Made: 1970s

Batteries:  AC Plug

I purchased the Compet CS-2302 from a local thrift store in Glendora, CA back in the summer of 2016. 

Adding machine, but where’s the tape?

The CS-2302 is a paperless desktop calculator, but retains the characteristics of an adding machine.  That is to add numbers, enter your number and press [ + = ].  The total is immediately displayed.  Same with subtraction, press [ - = ] to subtract. 

What is unusual about the CS-2302 is a lack of a subtotal or total key (normally marked [ ⋄ S ] and [ * T ], respectively).  Totals are cleared by pressing the clear button twice.

There is an exchange key [ ↕ ] on the CS-2302, something I don’t ever recall seeing on an adding machine.

The CS-2302 has two memories, M and I.  There are separate memory add and recall keys dedicated to both memories.

The keyboard is very solid.  The keys are responsive and it was well maintained. 

The Very Bright Display

The CS-2302 in a dark room

I think the CS-2302 wins the award for having the brightest display when it comes to calculators. 

The Red Negative Indicator

Even more amazing is the multi-color display.  Yes, in 2017 we live in a world where multi-color displays on calculators are close to common place:  HP Prime, TI-84 Plus CE, TI-nSpire CX, Casio Prizm, and Casio Classpad fx-CP400.  However, the CS-2302 is from the 1907s: a red negative sign indicator. 

Modes

The usual adding machine modes are present:  Constant Mode toggle (K), fix decimal selector complete with Add Mode, and automatic summation (Σ) toggle.

If you are not familiar with Add Mode, it is a mode where the all sums are rounded to 2 decimal places.  You are allowed to add and subtract numbers in dollars and cents without having to press the decimal point key [ . ].  Add Mode is a favorite of many office workers.

Item Counts, AVG, MU

The Item Count adds the number of addition and subtraction operations.  Pressing [IC] gives the item count and twice to clear it.

You can also use the item count to get the average of numbers added by one step with the average key ([AVG]).  Calculating the average clears the item count automatically.

Sharp called the [MU] the multiple use key in the 1970s.  Now the key is called the mark-up key.  It is true that [MU] serves multiple purposes.  Looking at the manual from similar desktop calculators from Sharp, the [MU] allows for cost, sell, markup, margin, and percent change calculations. For example:

Percent Change:  new [ + ] old [ - ] [ MU ]

Selling Price:  cost [ ÷ ] margin [ MU ]

Markup:  sell [ + ] cost [ - ] [ MU ]

Final Verdict

I love the display of the CS-2302 and the big size and steady keyboard.  I wish the CS-2302 had a totals key [ * T ] to complete calculations.  This desktop calculator, and others like it, would be a good ecological alternative for those who don’t want paper tape. 

Eddie

This blog is property of Edward Shore, 2017