How to Build an 8-Bit Computer

Step 18: Going Further

I hope you enjoyed this Instructable and, most of all, I hope that you got something out of it. You can consider all of this hard work an incredibly valuable learning experience that will give you a better understanding of electronics, computers and programming. In the end you will also have something very cool to show for all of your hard work as well.

After constructing your first 8-bit computer you can go further and add more functionality. The ALU used in this computer is very simplistic in operation and true ALU's today have a myriad of functions such as bit-shifting and logical comparisons. Another important aspect to move onto is conditional branching. Conditional branching means that an instruction depends on the current state of flags set by the ALU. These flags change as the accumulator's contents become negative or are equal to zero. This allows for a much more expansive possibility for application of your computer.

If you have any questions about this project feel free to comment on this Instructable, comment on my website at http://8bitspaghetti.com or shoot me an email at [e-mail]. I wish you the best of luck with this project.

Comments

[superaxander]

How long did it take to build it.

[waldosan]

this is commitment dude, i can barely begin to comprehend this, (decimal binary was throwing me through a loop...) is it scale able in the sense that if you made two of these you could have a more powerful 8 bit computer or would it be scale able in the sense that making two of them makes a 16 bit machine? i'm favoriting this and reading it over until i understand it...

[spel3o]

It's not really in a scaleable sense unless you worked out some way for them both to run in parallel. It would be a lot more simple to design a more efficient architecture and up the clock speed. And feel free to read it over as many times as you want, I had to do the same with my book to get a full grasp of everything I needed for this project.

[ncheriyan]

u rock dude......u know what,i'm gonna kill u and cut your brain and preserve it for the future generation......................even einstein will bow down to u....................................................hi hi hi

[waldosan]

that's still quite amazing! wouldn't upping the clock speed increase the heat output of the entire system like in a conventional computer? and are you thinking of mounting this on a pcb anytime soon? i think it'd be kinda fun to try and do this in fritzing.

[schmitta]

Very cool. My freshman year at Virginia Tech (1969) we had a guy on the hall designing a computer from scratch. I don't remember what ICs we had back then but for his memory he was going to use an endless magnetic tape with a read / write head. he would store a section of bits on the tape when he got to the right location and read memory when the tape was at the right spot in memory. I would like to know what happened to that guy and what he is doing now. Either he or his roommate discovered girls that year and I think that put a kink into his computer plans.

[waldosan]

it's like xkcd said, when geeks get girlfriends projects get orphaned...