LearnSCADA 6502 Emulator

6502 Emulator

A small 8-bit computer that runs in your browser, with a real 6502 processor and Microsoft BASIC 1.1 from 1978. Type a line, press Return, and the computer answers, the way people first learned to program.

It is the computer from the book Learn BASIC and Assembly on the 6502: every listing in the book runs on it exactly as printed.

Open the Emulator

The LearnSCADA 6502 Emulator running a BASIC program, with the Machine Code Workbench beside the screen
The emulator, with the Machine Code Workbench open.

What you can do

Write BASIC programs

Microsoft BASIC 1.1 for the 6502, the same BASIC that shipped in the home computers of the late 1970s. Programs you SAVE stay in your browser.

Step through machine code

The Machine Code Workbench assembles 6502 code into memory. Step one instruction at a time, set breakpoints, and watch the registers, the stack and memory change.

Run a water plant over Modbus

The Fieldbus tab connects the computer to a simulated water treatment plant. Read its tank levels and pressures and switch its pumps from BASIC or machine code, over Modbus TCP.

Quick start

  1. Press Start the Computer.
  2. Type PRINT "HELLO" and press Return.
  3. Try a program:10 PRINT "HELLO" 20 GOTO 10 RUNPress Esc to STOP it, and type LIST to see it again.
  4. Reset restarts the computer. Anything not saved is lost.
  5. Files downloads your saved programs and uploads programs from your computer.

For a desktop or laptop with a keyboard. It is not made for phones or tablets.

The book

Learn BASIC and Assembly on the 6502 by Charles VanceComing soon

From your first PRINT to 6502 machine code and a working connection to a plant over Modbus, written for this emulator.

Free with a LearnSCADA account. Join as a Free Reader at no cost, or sign in.

Open the Emulator

LearnSCADA 6502 BASIC Emulator. Includes Microsoft BASIC for 6502, Version 1.1, Copyright (c) Microsoft Corporation, MIT License.