Show us your gear!

[surroundsoundman]

Sweet. This summer I may be building one, depending on when I get this hip surgery and recover.

Good Luck to you with your hip and a rack build. Helpful Tip... The best thing that I did was to put wheels on the bases. It makes life so much easier when you need to add, remove, or connect anything.

 

[surroundsoundman]

And the highlight to me is the Predicta TV's. Do they work?

The answer is really no. But the Predictas do light up, but due to internal component degradation over the years, you really want to unplug them asap.

 

[MidiMagic]

WOW, You had a slide rule ?
All I had was an Abacus !

 

[MidiMagic]

WOW, You had a slide rule ?
All I had was an Abacus !

Wow! 13 digit.

Did you know that, before this was a game, it was a calculator?

8-digit, with 8 registers.

This was the counting board. And it is why the desk with the cash register is called a counter. It was carved into one end of the counter.

A special marker (not part of a checker set) placed the decimal point. I know how to add, subtract, multiply, divide, and extract square roots on one.

The game appeared when clerks with nothing to do played checkers.

 

[ar surround]

Wow! 13 digit.

Did you know that, before this was a game, it was a calculator?

View attachment 112487

8-digit, with 8 registers.

This was the counting board. And it is why the desk with the cash register is called a counter. It was carved into one end of the counter.

A special marker (not part of a checker set) placed the decimal point. I know how to add, subtract, multiply, divide, and extract square roots on one.

The game appeared when clerks with nothing to do played checkers.

Link? I must find out how to calculate a square root using a checker board!

 

[mandrix]

Wow! 13 digit.

Did you know that, before this was a game, it was a calculator?

View attachment 112487

8-digit, with 8 registers.

This was the counting board. And it is why the desk with the cash register is called a counter. It was carved into one end of the counter.

A special marker (not part of a checker set) placed the decimal point. I know how to add, subtract, multiply, divide, and extract square roots on one.

The game appeared when clerks with nothing to do played checkers.

Well that's mostly true as I can find no reference to the game of checkers. However grids were used with counters for calculations.
I confess I did have to google this one, and not to rain on your explanation but out of curiosity.

 

[stevendive]

Most often the most important part is the antenna.
Unless you run a 50-100 foot long outside wire, pickup up much is very iffy.

That’s very likely to be at least one reason ours didn’t work. I don’t remember anyone running a wire out the window, let alone a long enough one.

 

[timothyemerson]

Wow! 13 digit.

Did you know that, before this was a game, it was a calculator?

View attachment 112487

8-digit, with 8 registers.

This was the counting board. And it is why the desk with the cash register is called a counter. It was carved into one end of the counter.

A special marker (not part of a checker set) placed the decimal point. I know how to add, subtract, multiply, divide, and extract square roots on one.

The game appeared when clerks with nothing to do played checkers.

I recently saw a YouTube video on how to perform the calculations! Pretty interesting. Can't for the life of me remember how to do it though. Some diagonal sliding involved.

 

[atlantasteve]

I finally have the audio home theater I always wanted…Until I want something new.

 

[MidiMagic]

Link? I must find out how to calculate a square root using a checker board!

This is a bi-quinary calculator. It is similar to Roman numerals, except that placing a 1 to the left of a 5 does not work.
Each row is a register. It contains one number.
Use some kind of marker to locate the decimal point for each register..
Use another kind of marker for the carat for finding the multiply/divide decimal.
Each digit (square) has up to 4 counters in the space and one counter on the line to the left (and slightly up) to indicate 5.
The four arithmetic functions on an abacus or counting board are elementary.
Long division can be accomplished by alternately using two registers for the partial products.
Decimal point placement is the same as in normal arithmetic.

The square root is taken using Newton's method of approximation.

Place the decimal point as far left as the original number needs space to fit in. Digits to the right of the decimal point are the accuracy of the result.

1. Make an initial guess.
2. Divide the original number by the guess
3. Add the quotient to the guess
4. Divide the sum by two
5. If the result is equal (or close enough for your purpose) to the guess, then stop. You have the answer.
6. Copy the result into the guess register as the new guess and repeat steps 2 thru 6.

Note that steps 3 and 4 are averaging the guess with the original number divided by the guess.

With the counting board/checkerboard, you need these registers (rows on the checkerboard):

Original number
Guess
Two partial quotient registers (part of the long division process.)
Quotient/sum/result (the addition and division by two can occur in the same register).

You can get double precision (and longer calculation times) by putting two checkerboards side by side.