Me and my friend spent last weekend making a 2 bit computer out of ONLY household items.

What we used:

-6 nails
-3 miniature cardboard boxes
-6 low charge magnets
-tons of wire



anyways, no picture yet, my friend is gonna give me a few pictures on monday -- hopefully by then we can allow for writing of programs in nibble hex using switches

Here's the plan on what the possible opcode table will be:

0 - NOP
1 - ADD O, A, B
2 - SUB O, A, B
3 - ADD A, B
4 - SUB A, B
5 - OUT A
6 - OUT B
7 - IN A
8 - IN B
9 - AND A, B
A - LD A, PC$ + 1
B - LD B, PC$ + 1
C - OUT PC$ + 1
D - AND A, B
E - IN PC$
F - RET

To do this program writing however, we'll need more materials -- we'll try to find the cheapest switches available ;D and more copper wire, we already use a full roll

As an EE, that post makes little to no sense to me. First, your opcode table consists of values that need four bits for representation, not two bits. Secondly, you mention nothing about a power source. Third, you don't mention how many registers you have, how the registers are stored, where the program memory is and how big it is, etc. I guess there's at least O, A, B, and PC? Are those what are two bits each?

Most importantly, wire and magnets do not a computer make.

So, this is more of a combinational logic computer rather than a sequential logic computer? How do you expect to program with that? Are you making it sequential logic? If so, it's not really only household items. Transistors and/or IC chips aren't exactly household in general concept.

Being a pre-EE myself, I must second much of Kerm's post.

With no mention of transistors, resistors, ICs, or anything that could be used to create logic gates, I'm unclear what exactly is going on.

Furthermore, why 2 bits? Simplicity? Part limitations? For the heck of it? If I were ghetto-rigging a computer, I'd go at least 3 or 4 bits.

That's part of it, I can't figure out what of it is two bits, unless he means it in the sense of "two-bit"=="cheap".

I never really thought of that but it might be the most likely explanation.
A ghetto-rigged computer IS pretty two-bit, heh.

Well, at least one of a hundred questions have been answered. Maybe.

Maybe. I guess we'll find out for sure once Ashbad returns to enlighten us.

Ohaithur,

Yeah, I left out how I didn't include 3 AAA batteries x.x my bad.

Yeah, I was able to get an OR instructor working without any transistors and such, just pure wires -- and that was about it x.x me and my friend reworked it to be 4 bits, since 2 seemed too small a number to really even care about. I guess I left a ton out of that post, didn't I? X.x my bad again. But it worked for that one instruction at least. We are now working out more registers, (more specific ones, we already made A, B, C, D, E, F, G, I, O, PC$, PG$, and about 8 others, and we literally already have them functioning -- and each has a different amount of wire hooks attached based on it's use, and as you can imagine A and B are basically wearing 100 hook studs) and actually have some other hardware elements working.

We're just doing it for fun, but the part we want to emphasize is the fact we are gonna use as little current or even technology less than 50 years old on this. We want to relive the glory days of the 30's computer science

Yeah, I know you're gonna call it naive, but i've had my naive stage in almost every language I use now, and with building other stuff, and you can't learn without doing something naive first

And who knows, it should work in the end (with a few prayers) but It might even turn out to be cool

Well yeah, OR is the only thing you can make with just wires. I have no idea how you plan to implement anything other that OR with just wires; in the glory days of *60s computer science they were using transistors (and in the 30s-50s, vacuum tubes that did essentially the same thing). How to do you propose to make AND, XOR, and NOT gates?

I'm still thinking it out -- and not to sound rude, but we don't really want much help we want to see how much we can figure out and learn first.

Aww, darn. Because I was going to suggest electromagnetic switches ( solenoid valves! ) to physically move wires and the like.

That doesn't sound rude at all, I admire your sense of experimentation. However, I caution you to not hesitate to ask for help when you do get stuck, because I know several possible answers and solutions to the questions I posed to you.

Actually, we thought of that one an hour ago

And Kerm, we will be sure to ask for help, I'm sure there are tons of things we need help with understanding -- and thanks for your support of our experimentation

CDI: I believe in common parlance that device is called a relay Ashbad, any time. I hope you'll keep us up to date on your progress (and I'm not sure whether the failure was on Cemetech's end or yours why you didn't see the response to the topic ).

Yeah, I know. But what's the fun in calling it what it is? A relay sounds boring anyway

Psh, that's nothing, this dude made a 16-bit CPU in minecraft

http://www.youtube.com/watch?v=7sNge0Ywz-M

Yeah, but you can't exactly build a Minecraft out of cardboard and nails.

You can make it out of coffee and programming (Read: Java)

Only 16 bits? How disappointing
Have to admit, it does take skill to make something that complex out of redstone. I can barely rig a double door to open from both sides with push buttons.