Here's to the systems programmers – Writing Hello World on a home brew CPU

It sounds cool and interesting but has almost no detail. Come on, Jack! Give us some details, RTL, code, board schematics, whatever.<p>@ All<p>This is how you do homebrew CPU&#x27;s and presentation best:<p><a href="http:&#x2F;&#x2F;www.homebrewcpu.com&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.homebrewcpu.com&#x2F;</a><p>Links to others for anyone wanting to learn about this stuff:<p><a href="http:&#x2F;&#x2F;www.homebrewcpu.com&#x2F;links.htm" rel="nofollow">http:&#x2F;&#x2F;www.homebrewcpu.com&#x2F;links.htm</a>

I really wish he&#x27;d document even the barest scraps of the CPU architecture. Is it microcoded? There&#x27;s 7400 series like 7402 or 7473, and there&#x27;s 7400 series like 74154, 74181, etc.<p>&quot;hey kid, I built one of these too, back in the day, and it was damn hard and time consuming, but oh a labor of love. I had no internet, nor any schooling. I read articles in Popular Electronics and I read the TI 7400 series databook. Then I reread them. Then I reread them.&quot; Yes, in fact it was snowing, uphill, and I in fact had no shoes!

&gt; Built from simple logic chips, it runs at a blistering 4MHz, has 32kb of RAM<p>I know that the author was being sarcastic, but really, 4MHz with 32kb of RAM is like state of the art 80&#x27;s technology. The fact that we are even able to get to this point with protoboards and discrete off-the-shelf logic chips is impressive.<p>I mean, I learned how to program back in 1988 in a computer not much more powerful than that.

I wrote Hello World for my relay computer- only 27 lines (uses self modified code, same as Jack!):<p><a href="http:&#x2F;&#x2F;relaysbc.sourceforge.net&#x2F;example-code.html" rel="nofollow">http:&#x2F;&#x2F;relaysbc.sourceforge.net&#x2F;example-code.html</a>

Any idea where I could go about learning to do this myself? A few google searches mainly led me to things saying it was impossible.

Fantastic achievement. Would love to know some more details about the project and hardware design.

Does it do pipelining, branch prediction and (hyper)threading? How is its memory hierarchy (cache levels) organized? Does it support a privileged mode? Does it support hardware page faults? Did you implement floating-point operations?<p>&gt; In order to be able to program it at all, I wrote a very simple compiler (strictly speaking it’s actually an assembler)<p>Does that compiler&#x2F;assembler run on your hardware?