Chips › Processors › 6502 family › MOS 6502
MOS 6502
1975
MOS Technology's cheap 1975 8-bit CPU that powered the Apple II, Commodore PET, BBC Micro and Atari machines.
Emulators
| Emulator | Type | License | Site |
|---|---|---|---|
| Acorn Atom | online | GPL-3.0 | Website ↗ |
| Altirra | downloadable | GPL-2.0 | Website ↗ |
| Apple2TS | online | MIT | Website ↗ |
| AppleWin | downloadable | GPL-2.0 | Website ↗ |
| Asteroids | online | Public domain | Website ↗ |
| Atari 5200 | online | MIT | Website ↗ |
| Atari++ | downloadable | GPL-2.0 | Website ↗ |
| Atari800 | downloadable | GPL-2.0 | Website ↗ |
| Atari800MacX | downloadable | GPL-2.0 | Website ↗ |
| B-em | downloadable | GPL-2.0 | Website ↗ |
| Battlezone | online | Public domain | Website ↗ |
| BeebEm | downloadable | GPL-2.0 | Website ↗ |
| BizHawk | downloadable | MIT | Website ↗ |
| Catakig | downloadable | BSD-2-Clause | Website ↗ |
| Centipede | online | Public domain | Website ↗ |
| ElectrEm | downloadable | GPL-2.0 | Website ↗ |
| ElkJS | online | GPL-2.0 | Website ↗ |
| Elkulator | downloadable | GPL-2.0 | Website ↗ |
| Epple II | downloadable | GPL-3.0 | Website ↗ |
| Fujisan | downloadable | GPL-2.0 | Website ↗ |
| Gemulator | downloadable | Freeware | Website ↗ |
| JS7800 | online | GPL-2.0 | Website ↗ |
| JVic | both | Apache-2.0 | Website ↗ |
| LinApple | downloadable | GPL-2.0 | Website ↗ |
| MAME | downloadable | GPL-2.0 | Website ↗ |
| Mednafen | downloadable | GPL-2.0 | Website ↗ |
| Missile Command | online | Public domain | Website ↗ |
| OpenEmu | downloadable | BSD-3-Clause | Website ↗ |
| OpenEmulator | downloadable | GPL-2.0 | Website ↗ |
| PET 2001 Emulator (masswerk) | online | Freeware | Website ↗ |
| Plus/4 | online | MIT | Website ↗ |
| Pravetz 82 | online | MIT | Website ↗ |
| Provenance | downloadable | BSD-3-Clause | Website ↗ |
| Rainbow | downloadable | Freeware | Website ↗ |
| RetroArch | both | GPL-3.0 | Website ↗ |
| Sfotty Pie A8 | online | MIT | Website ↗ |
| Tempest | online | Public domain | Website ↗ |
| VIC-20 Emulator (mwenge) | online | Unlicensed | Website ↗ |
| VICE | downloadable | GPL-2.0 | Website ↗ |
| Virtual ][ | downloadable | Commercial | Website ↗ |
| Xformer | downloadable | Freeware | Website ↗ |
| appl.emu | online | MIT | Website ↗ |
| apple2js | online | MIT | Website ↗ |
| b2 | downloadable | GPL-3.0 | Website ↗ |
| beebjit | downloadable | GPL-3.0 | Website ↗ |
| c128 | online | MIT | Website ↗ |
| jsA8E | online | Freeware | Website ↗ |
| jsbeeb | online | GPL-3.0 | Website ↗ |
| microM8 | downloadable | Freeware | Website ↗ |
| oric1js | online | MIT | Website ↗ |
Machines
Acorn Atom
Acorn Electron
Apple I
Apple II
Apple II Plus
Apple IIe
Asteroids
Atari 400
Atari 5200
Atari 7800
Atari 800
Atari 800XL
BBC Micro Model A
BBC Micro Model B
Battlezone
Battlezone
Centipede
Centipede
Commodore PET 2001
Commodore PET 4032
Commodore PET 8032
Commodore Plus/4
Commodore VIC-1001
Commodore VIC-20
Gauntlet
Missile Command
Oric 1
Pravetz 82
Tempest
Tempest
Reference & documentation
External technical references for programming the 6502 and for writing 6502 emulators.
| Resource | Type | Notes |
|---|---|---|
| MCS6500 Family Hardware Manual ↗ | Datasheet | Official electrical, timing, and signal specifications |
| Rockwell R650x/R651x Datasheet ↗ | Datasheet | Original 6502 pinouts and specifications (PDF) |
| 6502.org MOS Datasheets Archive ↗ | Datasheet | Original MOS/CSG datasheets for 6502 family chips |
| WDC W65C02S Datasheet ↗ | Datasheet | CMOS 65C02 timing and electrical (PDF) |
| 6502 Instruction Set (masswerk) ↗ | Instruction set | Full opcodes, cycles, addressing modes, NMOS & CMOS |
| CPU Unofficial Opcodes (NESdev) ↗ | Instruction set | Undocumented opcode matrix, NMOS behaviour |
| NMOS 6502 Opcodes (6502.org) ↗ | Instruction set | Per-instruction hex, modes, flags, timing |
| 6502 Illegal Opcodes Demystified ↗ | Instruction set | Systematic map of undocumented opcodes |
| MCS6500 Family Hardware Manual ↗ | Pinout | 40-pin signal descriptions and package pinout |
| WDC W65C02S Datasheet ↗ | Pinout | 65C02 pin assignments and bus signals (PDF) |
| MCS6500 Family Programming Manual ↗ | Programming | Canonical assembly programming reference, 265 pages |
| 6502.org Tutorials and Primers ↗ | Programming | Lessons on decimal mode, overflow, stack, interrupts |
| Easy 6502 (skilldrick) ↗ | Programming | Interactive assembly tutorial with emulator |
| How Illegal Opcodes Really Work (pagetable) ↗ | Reference | PLA-level explanation of illegal opcodes |
| Decimal (BCD) Mode (6502.org) ↗ | Reference | BCD and flag quirks across variants |
| SingleStepTests 65x02 ↗ | Test suite | Per-instruction JSON tests with bus activity |
| SingleStepTests ProcessorTests (6502/65C02) ↗ | Test suite | Per-opcode JSON tests with cycle-level bus activity |
| Klaus Dormann Functional Tests ↗ | Test suite | Functional, interrupt & decimal test ROMs |
| Visual6502 (transistor-level sim) ↗ | Tool | JavaScript transistor-level die simulation |