Advanced Redstone Computer Tutorial ?: ALU design

This video simply talks about what a good ALU design is and how we implement it

[bennyscube]

They work very similarly to real life electronics. The big differences are logic gates are made with transistors, there's a ground wire (no big deal), you need to have enough voltage and current to trigger but not damage the hardware (can require math, but usually not too bad), and optimization has different considerations. (For example, insta-carry doesn't work since you can't physically block/unblock current, so you use lookahead logic.)

Other than that, they work almost exactly the same way.

[bennyscube]

Sure I'd love to see your display! I think it'd be quite challenging to make a compact display without a BCD decoder, so I'm definitely interested in seeing it :)

[bennyscube]

I appreciate that you want to follow me building a computer block by block. After all, that's part of the learning process. Here's the thing though: The computer I'm going to show you won't be optimal in all situations and will eventually be obsolete. As such, I'm also trying to show how a computer is built and why so people can make this and better on their own.

If the only thing you get from this is a working computer then you've missed the point of this series.

[bennyscube]

It's common for things such as division algorithms, and isn't overly easy in software.

[prehistoricBanana]

I would like to add to your comment by saying that the carry can be stored in a flip flop and added to the next addition with another similar instruction, it can be ignored like bennyscube said but this allows a 16 bit computer to calculate 32 bit numbers.

[WillDixonE]

I love your tutorials! You don't show but explain what you do. It makes everything so clear. Just wish the tutorials would come faster lol. I know you do other stuff then jut tutorials i just don't know what to do on minecraft right now lol. Oh btw I would like you to check out my 4 bit to 9 segment display that i built my self. Wondering if i could make it smaller. goal was to skip decoding to decimal

[bennyscube]

Simple, you ignore it. In some cases, you will use it for things such as branching, but for the most part it doesn't matter since there isn't another bit to carry to.

[bennyscube]

Absolutely, it'll be a fair size but most certainly not that big

[SebAndNick]

When I saw how small the chip is for a bcd and decoder for 7 segment display was in digital electronics, my jaw dropped.

[MClightOfDay]

You my friend, are devoted. Unless creative mode made it to the 360?

[austinh]

Your videos are very good, but I had one question on adders. If you have a 16 bit computer, what happens to the carry if it is on? I know it can't be 17 bit. Also, how do you set the speed of the clock in the computer? Thank you!

[rellsw]

I am thinking of implementing your design using redpower and wireless redstone chickenbones addition

[MClightOfDay]

And because benny is on a server. If he built a computer that big, it would be called the EoS machine. It would crash the server too.

[Dccopus]

I understood it perfectly, but I don't think I'm a genius :P

[crazystunts]

is building the ALU causing part 5 to be delayed?

[zxPivotManxz]

Yeah. I have built a several CPUs all in one Minecraft 360 world.

[MClightOfDay]

Don't you need a comparator? Wouldn't that go into the ALU?

[OsuFan]

will this computer fit in a 850x850 world because i have minecraft on the 360

[thewitchking]

Can you maybe post a relevant link to this whole thing on extracting other Boolean fncs. from an adder? Or does it not really work efficiently in real life?

[WillDixonE]

Now it is not compact, and Im not quit sure what a BCD decoder does so I used karnaugh map of each segment... its fast just not that compact. The display is slower then the decoder itself I think... but let me compress my world and I'll send you a link to it once uploaded