Hi all,

Can anyone link me to a 4bit computer step by step guide and kit???

You can purchase one like this:

http://www.retrothing.com/2009/07/new-g ... r-kit.html

but making your own is more fun

What about waiting for fridays 4bit computer?? Id like to show students the very basics of computing and this 4 bit computer i believe may provide some good understanding. However, I need to understand completely myself. Ive been getting into "How computers do Math" its a great boox by Clive Maxfeild also his book bepbop to the boolean boogie" however, without a real model like this 4bit computer i thing there may be still some trouble.

Id appreciate any step by step guide or how to build this 4 bit computer myself?? This student Jack, may provide some further study for students as well: http://web.mac.com/teisenmann/iWeb/adeptpage/menu.html

Any very basics would be great, even a logic simulator of an early computer would be great.

Hi. The whole project is explained step by step on both the project page available on this site and the youtube video. If you take the circuit diagram for a single binary adder (also on the project page) you could build just one of the 4 adders and see it working.

The circuit board for the whole computer is also available, although, with that many transistors, it takes a while to make.

None of my projects are commercial; I don't make kits. But everything you need to reproduce them is available on my site.

Can you tell me where i could purchase the circuit board, switches etc?? Your digram doesnt show the buttons kind of lost where to start.

im trying to build your machine in http://logic.ly/ http://mac.softpedia.com/progDownload/l ... 92611.html

Doesnt exactly work well for me my email is trevrox@gmail.com if you want to send a save file?? Just trying to get my head around this

Attached is a simulation of a single adder in CEDAR logic, you should be able to easily expand this to the 4-bit cascading adder design.

Thanks Simon, Your a legend. If I may, Ill post your message for others who may need help understanding the full-bit adder. Also attached is my Logicly file as well as Logicly method compared to WFF method for educational purpose:

The full-adder 'adds' the bits:

if A = 0, B = 0 and C = 1, the 'sum' is 1 since there is one bit, so the output is Carry = 0 and Sum = 1 (or 01 = 1).

if A = 1, B = 0 and C = 0, the 'sum' is 1 since there is one bit, so the output is Carry = 0 and Sum = 1 (or 01 = 1).

if A = 1, B = 1 and C = 0, the 'sum' is 2 since there are two bits, so the output is Carry = 1 and Sum = 0 (or 10 = 2).

If A = 1, B = 1 and C = 1, the 'sum' is 3 since there are three bits: carry = 1 and sum = 1 (or 11 = 3).

You are not inputting a binary number into the adders as such, you are inputting a number of bits to be counted. That's usually the part that confuses people

Hi

Here is what the 'complete' 4-bit adder would look like. I couldn't save the file from the web trial version Logicly, but it should only take a couple of minutes to recreate it.

Here is the sum it is performing:

A = 11 (b 1011)
B = 8 (b 1000)

A+B = 19 (b 10011)

Here is my failed attempt i was trying to recreate your version using and and or gates. so did you use XOR gates / Transisters for the final product as well if i was to recreate it??