Six Five Oh Two

SixFiveOhTwo is a complete WDC W65C02S CPU emulator that runs right on your Android device. Write 6502 assembly code, assemble it to bytecode in real time, and watch the CPU execute it — all from your pocket.

Full CPU Emulation

Included are all 56 base instructions, 15 addressing modes, 242 valid opcodes, BCD arithmetic, hardware interrupts (IRQ, NMI, BRK), and all 40 CPU pins (PHI2, RESB, NMIB, IRQB, address bus, data bus, and more). The 64 KB address space includes a zero page, hardware stack, general-purpose RAM, a 40×25 text display at $0400, and the standard NMI/Reset/IRQ vectors.

Native Assembly Editor

Write and edit 6502 assembly directly in a polished native editor with real-time syntax highlighting — mnemonics, labels, directives, registers, numbers, and comments are all color-coded. Save your programs by name, reload them any time, and delete them when you're done.

Built-in Example Programs

Hit the ground running with a suite of example programs covering many instructions, addressing modes, and common programming patterns: counters, memory operations, register transfers, subroutines, indirect addressing, flag/branch tests, multi-byte arithmetic, bit manipulation, sorting algorithms, interrupt handling, text display, BCD, and more.

In-App Reference Docs

Never leave the app to look something up. The navigation drawer gives instant access to a full Assembly Language Quick Reference and a complete Opcode Table — both available as overlays without interrupting your emulator session.

Persistent Storage

All your programs — example and user-written — are stored in a local database. Your work is always there when you come back.

Clean Tabbed UI

The emulator's tabbed interface lets you inspect the CPU registers, memory contents, individual pin states, and the text display output, all in a clean layout optimised for mobile screens.

Supports W65C02S extensions: BRA, PHX, PLX, PHY, PLY, STZ, TSB, TRB, WAI, STP, RMB0–7, SMB0–7, BBR0–7, BBS0–7.

Whether you're learning 6502 assembly, revisiting classic retro computing, or exploring low-level programming on the go, SixFiveOhTwo puts a complete development and execution environment in your hands.