Build a 6502 based computer

6502 sbc

I wanted to design and build a computer that’s based around the 6502 microprocessor. When I say build a 6502 computer, I mean a computer that has been built from scratch! When people say that they have built a PC, what they have done is put together circuits and peripherals. To me, truly building a computer is building with discrete components, ICs, wires etc. I hope that by following this project, people will find it of interest, learn something and that some will want to build their own.

For a computer to be useful, it needs to be able to store and run programs. Once the computer is at this stage, I want to then write programs in assembly. You don’t have to know 6502 assembly to understand the contents of this course but I encourage you to learn about it, as it will cement your understanding of many important concepts. I have a course on 6502 assembly language.

There are a number of prefixes that I will be using throughout, these are shown in Table 1, with their meaning.

PREFIXMEANINGEXAMPLE
#decimal value#22
#%binary value#%10010110
#$hexadecimal value#$EE
#’ ‘ASCII value#’B’
memory address in decimal1001
$memory address in hexadecimal$1101
table 1. data types

Each section of the computer could be made with a multitude of different components. However, with my design, there is a stipulation that I would like to make – that the ICs are of the era of the 6502. The 6502 was introduced in 1975 and I have decided that ICs will be used in my design if they were introduced in the 70s.

For each of the images that I have created, you can click on them to see an enlarged version, on a separate page.