Vpsmall
Viktor writes –

I’ve been a software guy all my life. However, I was always fascinated by electronics, and part of my success as a programmer was due to my thorough understanding of how computers work.

Back in 1999, I put that understanding to the ultimate test: I actually designed, and built, a simple but functional 4-bit computer from low-level electronic components (TTL logic gates.) Although this machine has less then one tenth of a percent of the speed and one millionth of the memory of a modern Pentium system, not to mention that its “user interface” is just a set of miniature switches and blinking LED lights, I still consider this a proud accomplishment.

If you are insterested, you can study a full description of this system, including logic diagrams and more. Or, if you just want an overview, here’s a photo and, to demonstrate the programming model of this processor, a small program that multiplies two 4-bit numbers to obtain an 8-bit result…

Viktor’s Home Page: Viktor’s Amazing 4-bit Processor –Link.