Build my own calculator

G

Gunnar G

Guest
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?
 
Gunnar G wrote:
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?
Click to expand...
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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"Gunnar G" <debian@comhem.se> schreef in bericht
news:nfHre.27282$d5.179310@newsb.telia.net...
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?
Click to expand...
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
 
petrus bitbyter wrote:
"Gunnar G" <debian@comhem.se> schreef in bericht
news:nfHre.27282$d5.179310@newsb.telia.net...

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?


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
Click to expand...
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.

--
If a little knowledge is dangerous, where is the man who has
so much as to be out of danger?
Thomas Henry Huxley, 1877
 
petrus bitbyter wrote:

I was told that Microchip has a application note
treating floating point calculations but I did not check out myself.
Click to expand...
Many AVR processors can use the floating-point routine in the file
library.
http://members.tripod.com/Stelios_Cellar/AVR/AVR_File_Archieve.html

I googled for
avr floating-point

The link above is one of the links I found.


Multiply and Divide Routines
<http://www.avrfreaks.net/index.php?module=FreaksTools&func=viewItem&ite
m_type=tool&item_id=66>

Using the AVR Hardware Multiplier Updated: Feb 24, 2005
Examples of using the multiplier for 8-bit arithmetic.
<http://www.avrfreaks.net/index.php?module=FreaksTools&func=viewItem&ite
m_type=tool&item_id=67>

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.


--
Roger J.
 
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.
 
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