Logisim - A logic simulator I've built an 8-bit CPU in

[Nikita]

I know, but I find it more fun to place chips and wire them up



That happens when you create an "infinite loop". It always takes some time for a gate to handle a data input and then output, so if you are creating a circuit like this, you will have an infinite loop:

Well it does it even if I make a simple RC-latch.

[Matte]

matte can we get a save for that cpu? i want to see how you made all that crazy stuff plz :P

I can give you a save when it's done. I need to add register support and memory management.

I also need to write some docmentation on how to program it.

[Whodunnit]

logism was already in another thread, but that processor owns, another program is also atanua, but taht lacks soem necessary features to truely work well.

We use Quartus 2 to program our FPGA's at uni.


also of interest is "logic friday"
which can take trusth tables and perform complex boolean simplification for you so you dont need to do it by hand.

#include <iostream>
#include <windows.h>

bool A=0,B=0,C=0,D=0,E=0,F=0,F0=0,F1=0,F2=0,F3=0,F4=0,F5=0,reset = 0;    
int counter = 0;

int main(){

    while(1)
    {

        int temp = counter;
        F = temp % 2;
        temp = temp/2;
        E = temp % 2;
        temp = temp/2;
        D = temp % 2;
        temp = temp/2;
        C = temp % 2;
        temp = temp/2;
        B = temp % 2;
        temp = temp/2;
        A = temp % 2;
        temp = temp/2;

        F0 = A&!C&!D&E&F | !A&!B&!C&!D&!E&F;
        F1 = !A&!B&!C&D&!F | B&!C&!D&E&!F | !A&!B&D&E&F |!A&!B&!C&E&F| !B&!C&D&E&F | !A&C&!D&E&F  | A&C&!D&E&F | A&D&!E&F | !A&C&!E&F | A&!C&!D&!E&F | B&D&E&F | B&!D&!E&F | B&!C&D&!E ;
        F2 = B&C&!D&F | !A&C&!D&E&F | A&C&!D&!E&F | A&!C&!D&!E&F | B&!C&D&!E ;
        F3 = !A&!B&!C&D&!F | !A&!B&!C&!D&!E&F | B&!C&!D&E&!F | !A&!B&!C&E&F | A&C&!D&!E&F | A&C&!D&E&F | A&D&!E&F | !A&C&!E&F | B&D&E&F | B&!D&!E&F;
        F4 = !A&!B&!C&D&E  | B&C&!D&E&F | B&D&!E&F | !A&!B&D&E&F | !B&!C&D&E&F | A&C&!D&!E&F | A&C&!D&E&F | A&!C&!D&!E&F | B&!C&D&!E ;
        F5 = !A&!B&!C&!D&!E&F | !A&!B&!C&D&E  | B&D&!E&F | !A&C&!D&E&F | A&C&!D&!E&F | A&!C&!D&!E&F | B&!C&D&!E ;
        reset = A&B ;

        if(F0||F1||F2||F3||F4||F5)
        Beep(100*(F0*2*16+F1*2*8+F2*2*4+F3*2*2+F4*2*1+F5),100);
        else
        Sleep(100);


        if(reset)
            break;
        else
            counter++;

        std::cout << counter <<  " " << F0*2*16+F1*2*8+F2*2*4+F3*2*2+F4*2*1+F5 <<" " << F0 << F1 << F2 << F3 << F4 << F5 << "\n"; 

    }

    return true;
}

thats a test of my digital tone generator in c++ using the PC speaker.



thats what we loaded to our FPGA, and we transmitted the song on an FM radio transmitter we built!

this was a little uni project that was quite fun, not as complex as matte's processor , but its an idea of whats possible. so long story short yeah wiremod helps you do university, and yes you dont need wiremod its just a gateway to ownage stuff as OP said.

[adadr]

ok i just installed this on my Win7 drive and turned off my pc for awhile and when i get back on, everything is running 10X faster. when i type A it types AAAAAAAA and all the loading screens fly by really fast. this may have caused this problem, this may have not, but i cant think of anything else that could have done it.

[Whodunnit]

installed what? logism? I dont think that it would cause anything like that ...

[Matte]

Hmm, it shouldn't cause anything like that. It works on my 64-bit vista, so I don't see why it shouldn't work on Win7.
Where did you download it from? Maybe the file contained malware.

[Matte]

I just wanted to say that I'm working on a 32-bit version of this 8-bit CPU right now, and writing proper documentation on how to program it (I'll probably write an assembler, too). This will be a more complete CPU with support for 65536 registers and 32-bit unsigned integers up to 4294967296. This is an upgrade of my previous 8-bit CPU, which only supported 128 registers and integers up to 127. The new 32-bit CPU will also support jumps and conditional jumps.

I'll upload the save here when I'm done, but if someone wants it, I can upload the 8-bit CPU too, even though I abandoned it, so it's not quite finished.

[Nikita]

Awesome Matte, I wanted to make something like CPU in logisim, but never got anywhere THAT serious.

Also, in before people pointing out pointlessness of doing things for fun.

[Whodunnit]

matte, 65536 different register? i dont understand why so many registers would be necessary. unless you meant ram addresses. next step buy alot of IC's and bread board it.

[adadr]

i dloaded it from the website. im on XP right now