Build my own calculator

At what level do you want to start? Calculator chip level? Programmable Logic? Discrete complex chips? Discrete simple chips? Resistors and transistors? Tubes? Beach sand to make silicon chips? Abacus? Piles of rocks?

Seriously, You're starting a project that is conceptually simple, but annoyingly complex to implement. And when you're done, it will be HUGE and useless.

Motivation is the key to learning. If you start with a weak goal and a frustrating path to get there, you'll never finish it.

Pick an outcome you can use when you're done and a simpler implementation path. Design a learning project around that. A lot of people start with home automation projects. mike

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mike
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The intel 4004 cpu chip was designed to put in a calculator. So why not get a dev bd like an olimex mt128 with an lcd and some buttons, and write a specialty calculator for it.

Reply to
BobG

The 12 and 16 series have no multiply operation, so the floating point libraries supplied by microchip are immense and slow. However, the current crop of low-end pics are almost certainly faster, and hold more code than the original HP calculators. A PIC18, with a multiply, would make it even easier.

On the other hand, you can buy a casio fx-115MS that does everything from complex numbers to integration for about $15, which is undoubtedly far less than you would spend on parts, not counting programmers and test tools to build it.

Another project, which is probably easier to pull off, and which will give you lots of puzzles to solve and a thing you can use at the end would be to build a VFD clock. You can get cheap vacuum fluorescent display tubes at surplus places, They look cool, but require you to design and implement various power supplies to handle the grid/filament/anode. Take the timebase off of the powerline, and use CMOS logic or something like that to generate the clock display. A microcontroller (PIC or something) would make it easier, but you would have to learn to program it.

That will be a fairly big project, not too hard, and you'll have an interesting looking clock afterwards, not a slow, feature-bare calculator.

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Reply to
Bob Monsen

Many AVR processors can use the floating-point routine in the file library.

formatting link

I googled for avr floating-point

The link above is one of the links I found.

Multiply and Divide Routines

Using the AVR Hardware Multiplier Updated: Feb 24, 2005 Examples of using the multiplier for 8-bit arithmetic.

If the goal is a pocket calculator a modern microprocessor is the perfekt choice. It has better instruktions and is a lot faster that the first pocket calculator processors.

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Reply to
Roger Johansson

Hi. Is it hard to build your own calculator? Now I'm not talking about something like the latest HP calculator but something between that and the ENIAC. The ability to add numbers would be a great start. Has anyone done this, any good internet resources for this?

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Gunnar G

"Gunnar G" schreef in bericht news:nfHre.27282$ snipped-for-privacy@newsb.telia.net...

Something in between is a wide, wide area. A calculator with only four basic functions can be build with almost any micro that has enough I/O-pins two read the keyboard and drive the display of your choice. It may become pretty slow if you go into larger numbers but it will nevertheless be faster then the Eniac. (But heavier, slower and more energy hungry then the next simple, cheap pocket calculator.) I was told that Microchip has a application note treating floating point calculations but I did not check out myself.

petrus bitbyter

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petrus bitbyter

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