Getting Started with 6502


I've decided to learn about the historically famous MOS 6502 chip to build my own computer. I'll be using the newer products from Western Design Center that include the W65c02 CPU.

These are notes made during my learning, designing and testing phases; I'm hoping they'll help you, too.


A Path to Learning 6502
 - Get a reliable flash drive and install EVERYTHING on it; mine is labeled  drive "J:"
 - Download "VASM assembler" for the 6502 for Windows 10 from and install it on "J:"  in a folder/directory named "Vasm". You'll need to copy the files from "J:\VASM\vasm6502_oldstyle\win\win10"
 - Search for the file location of "Command Prompt" on your Windows PC and copy its link to your J: drive
 - Startup your Command Prompt link which should take you to your home directory - "C:\Users\prefo" for me
 - Create a text file named "J.bat" and drop it in your home directory. The contents of the file are:
cd \Vasm


 - Confirm its contents by typing:

type J.bat

 - Now you can type "J.bat" or "J" to change to your J drive and the Vasm folder (J:\VASM).
 - Within J:\Vasm, create a text file named "Vasm.bat". (Here is a copy saved as "Vasm.txt" because Windows won't permit ".bat" files to be downloaded. It must renamed to "Vasm.bat" in order to run.)  The contents of the file are:
vasm6502_oldstyle.exe   -Fbin   -dotdir   -c02   %1.asm
HxD  a.out

 - Copy my "VIA.asm" file to your "J:\Vasm" folder
 - Execute "Vasm.bat" by typing:
Vasm  VIA

 - This will cause "Vasm6502_oldstyle.exe" to run and assemble "VIA.asm" into "a.out" which you can then examine with a hex editor like HxD. Actually, the batch file starts up HxD automatically
 - Install a hex editor (HxD20) into J:\HxD from site

This is a good start!


Here are some valuable resources:
 - Bookmark

 - Book 6502 Assembly Language Programming

 - Book: Programming & Interfacing the 6502, With Experiments

 - Book: 6502_Assembly_Language_Subroutines

 - Cheat sheet: 6502 Instruction Set

 - 6502 Instance Reference Card. I had this one laminated at Staples for $4

 - 6502 instructions cheat sheet... and another cheat sheet

 - WDC 65xx integrated circuits website

 - 20x4 LCD display panel document

 - ROM programming tool: XGecu TL866II Plus MiniPro

 - Chip labels


6502 Simulator:  and download


Learning Info and Other References:

 - Watch Ben Eater's nine Youtube video set: Build a 65c02-based computer from scratch

 - Some videos on building a 6502:



 - Life With David Youtube video watch order list

 - David Murray's six Youtube video set: Commander X16

 - Grant Searle design: 6502 SBC with only 7 chips

 - List of Assemblers and IDEs (integrated development environments)

 - info on MOS 6502 and WDC 65C02S

 - Programming Tips for the 65c02

 - Udemy training course: Learn Assembly Language by Making Games for the Atari 2600

 - Kindle Book: Programming the 65816: Including the 6502, etc.

 - WDC Single Board Computer development board: W65C265SXB SBC


                             CPU                                             ROM                                             RAM                                            VIA                                                   ACIA                                            UART