calculator in logic gates

[edepot]

I was recommended this URL in my email:

http://logic.ly/demo/

It seems to be a logic gate simulator. Although not an electrical engineer by trade, I succeeded in doing a 4 bit adder (no round-robin carry) using only three types of gates (AND, XOR, and OR). This must be the most inefficient implementation of a calculator in the world. But just so that this effort does not go to waste (and prove to myself I could do it), maybe there are people who are interested in this inefficient calculator.

logic gate calc

IMG_0515.jpg (168.4 KiB) Viewed 3493 times

The top left 4 switches are the first number. The bottom left 4 switches are the second number. Top to bottom is the order of the number from lowest bit to highest bit. The right half has the final answer (it displays a hex number based on the 4 bit input and the possible values are: 0123456789ABCDEF). In the example in the picture, 5 (top) + 3 (bottom) = 8.

[artmaker]

An even better implementation of Logic Gates to solve logic word problems and understand what is "under the hood" of all modern computers, go to this url and download the zip file version. It only contains an executible and one dll which you can keep together in its own folder - no installation is required with this approach. What is really cool is that you can start with basic circuits and then save them as an Integrated Circuit (so all the complexities are no longer in view). Then you use these ICs to construct even more complex circuits. The program is Open Source and is still being updated with more improvements to come in the future.

One word of caution. The computer that you use it on MUST have .NET 4 I am using Windows 7 64 bit and it is part of the operating system. If you are using XP, then the .NET 4 package can be downloaded from Microsoft.

http://www.kolls.net/gatesim/

Two excellent books to help you really learn digital logic:

"Code" by Charles Petzold
"Ones and Zeros" by John R. Gregg