Build your own calculator

[zeeming]

Hello,
I would like to build my own calculator. I am trying to build the mos
basic calculator that can simply add and subtract (and maybe multiply an
divide as well). What I am most interested in is the very heart of th
calculator, the processor, so to speak. I am interested in learning abou
how it works exactly so I can follow the path of each and every signal.
Essentially, I would like to build this processor piece by piece fro
scratch.

My email is bbobbage at yahoo.com

 

[Rich Webb]

Hello,
I would like to build my own calculator. I am trying to build the most
basic calculator that can simply add and subtract (and maybe multiply and
divide as well). What I am most interested in is the very heart of the
calculator, the processor, so to speak. I am interested in learning about
how it works exactly so I can follow the path of each and every signal.
Essentially, I would like to build this processor piece by piece from
scratch.

I'd download the free ISE WebPACK from Xilinx
<http://www.xilinx.com/ise/logic_design_prod/webpack.htm>
or Altera's free Quartus II Web Edition
<http://www.altera.com/products/software/products/quartus2web/sof-quarwebmain.html>

which will let you build your design gate-by-gate and then run it under
the enclosed simulation software. When it's time to make it "real world"
there are several inexpensive FPGA development boards you can use. This
is a much "nicer" alternative to wiring up a gazillion [*] discrete TTL
logic gates (although that's also a possible route). There is a learning
curve to creating a design via schematic layout in those packages but
it's a heck of a lot less time than wire-wrapping or breadboarding a
pile of discretes -- and you'll learn a useful tool in the process.

There are many sources for dev boards. A favorite site is
http://www.digilentinc.com/ where you can get boards and the
necessary JTAG programming dongles.



[*] Speaking of gazillion; shamelessly stolen from Blond Sense
<http://blondesense.blogspot.com/2005/12/you-just-know-it-could-happen.html>

Donald Rumsfeld is giving the President his daily briefing. He concludes
by saying. "Yesterday 3 Brazilian soldiers were killed."

"OH NO!" The President exclaims. "That's terrible!"

His staff sits stunned at this display of emotion nerivously watching as
the President sits, head in hands.

Finally, the President looks up and ask. "How many is a Brazillion?"

 

[Bob Monsen]

[*] Speaking of gazillion; shamelessly stolen from Blond Sense
<http://blondesense.blogspot.com/2005/12/you-just-know-it-could-happen.html>

Donald Rumsfeld is giving the President his daily briefing. He concludes
by saying. "Yesterday 3 Brazilian soldiers were killed."

"OH NO!" The President exclaims. "That's terrible!"

His staff sits stunned at this display of emotion nerivously watching as
the President sits, head in hands.

Finally, the President looks up and ask. "How many is a Brazillion?"

This one made me laugh... Thanks!

--
Regards,
Bob Monsen

Man, as a social animal, can no more escape government than the
individual can escape bondage to his bowels."