open 8-bit computer

MEGA65 is an open-source new and open C65-like computer.

The 21st century realization of the C65 heritage: A complete 8-bit computer running around 50x faster than a C64 while being highly compatible. C65 design, mechanical keyboard, HD output, SD card support, Ethernet, extended memory and other features increase the fun without spoiling the 8-bit feel. Hardware designs and software are open-source (LGPL).








GEOS Adaption




Software Bundle


Brand Establishment


Lines 6502 asm code


GIT Commits


Lines of VHDL






People involved


Working hours


Days invested


MEGA65 facts

For those interested in details, here are some current technical specifications of the MEGA65. These details are subject to change as we progress through the project.


  • 50MHz GS4510 single-core, in-order, no-branch-prediction, no-cache, single-scalar, no-fpu, no-smd, no-HCF, non-pipelined, enhanced 4502 8-bit processor

  • Including:
  • 32-bit ZP indirect and 32-bit far-JSR/JMP/RTS operations
  • 28-bit address space
  • Fast hypervisor traps
  • Virtual memory
  • IO virtualisation (coming soon)
  • Synthmark64 score: 51.1x (C64 = 1x)
  • Bouldermark score: 32,509 (C64 = 313)


  • C65 DMAgic compatible DMA controller
  • Fills at 50 MB/sec, copies at 25 MB/sec, swaps at 12.5 MB/sec
  • VIC-IV advanced rasterised video controller, like the VIC-II and VIC-III no framebuffer
  • Native resolution 800x600 (100MHz pixel clock)
  • Supports all documented VIC-II modes (hi-res, multi-colour mode, extended-background-colour mode, sprites) and VIC-III modes (bitplanes are in the process of adding)
  • Independent horizontal and vertical hardware scaling allows text and graphics resolutions as high as 800x600 and as low as 60x38
  • Separate 256-colour palettes for sprites, bitplanes and character graphics, allowing upto 1,024 colours on screen without changing the palette in real-time
  • VGA and HDMI output 23-bit colour (8.3 million colours)
  • Text mode extensions including proportional width characters, super-extended background colour mode, as well as the standard VIC-III extended attributes
  • Dual soft-SIDs + optional dual hard SIDs
  • D81 disk images from SD card (native VFAT32 file system support coming soon).
  • Real 3.5" floppy drive support

  • Loading speeds:
  • Without fast loader: ~20KB second
  • Directly from SD card: 300 - 3000KB/second (1200 - 12000 blocks per second), depending on SD card
  • Joystick ports 1 and 2 (9-Pin Atari Standard)
  • HDMI
  • VGA
  • 10/100mbit Ethernet
  • Stereo audio
  • C64 type expansion port
  • IEC disk drive port
  • Internal expansion port
  • USB and Micro USB debug interface

  • Planned:
  • Analog video
  • Micro USB debug interface
  • Ethernet
  • Micro SD slot
  • MEGA-OS all-in-one hypervisor and compat operating system

  • Including:
  • Integrated freezer and task switcher
  • VFAT32 file system driver
  • Inter-process communications
  • C65-like all-in-one
  • Right now:
  • Use Ophis with the -4 option to target the 4502 CPU. The etherload utility can be used to push compiled programs to the MEGA65 practically instantly to make for a convenient cross-platform development environment.

  • Upcoming:
  • MEGA-OS will support interprocess communications, making it possible to write assemblers and compilers that assemble directly into a separate process, and then launches that process when it is ready. Thus it becomes possible to use the MEGA65 as an 8-bit development platform for 8-bit software (or to run a cross-compiler for Linux or Windows if you wish to be really strange).


  • 1st
    half of


    20 machines to heat things up

    Production of the first batch of developer machines. These are dedicated to key stakeholders: Software developers, former C65 engineers, community influencers and journalists of retro-magazines.

  • 2nd
    half of


    Experts building the MEGA65

    MEGA identifies further strategic partners, ideally suited for producing MEGA65 hardware components: GMK electronic design as expert for keyboard design and production; Hintsteiner Group being specialized in case tooling and production, and Trenz Electronic as creator of mainboards, for assembly and distribution.

  • 1st
    half of


    MEGA65 rev.1 board

    Trenz produces MEGA65 rev.1 mainboard. The prototypes are presented over Easter at the world-renowned demoscene-party Revision in Saarbrücken.

  • 2016


    1:1 copy of the C65

    MEGA65 presents the 2nd prototype, an exact replica of the original C65. More experts join the MEGA65 team: Software engineer Ralph Egas, technical writer Andrew Owen and FPGA guru Antti Lukats from Trenz Electronic GmbH, first strategic delivery partner of the MEGA65 project.

  • 2nd
    half of


    Artix-7 plus MEGA65 extension

    Hardware engineer Dieter Penner joins the project which delivers the first alpha-series prototype. It leverages Digilent's Nexys 4 Artix-7 FPGA development board and a case closely resembling the original, produced in a selective laser sintering (SLS) prototyping process.

  • 1st
    half of


    MEGA65 project starts

    Thinking about creating a C65 demo, MEGA board member Detlef Hastik immediately realizes the potential of Paul's concept. With MEGA's thrive for preserving mankind's digital heritage, the idea is born to re-build C65 computers, Paul joins MEGA. MEGA member Andre Kudra gets hold of a working C65 as study object.

  • 2014

    The creator

    slightly mad scientist

    Paul Gardner-Stephen once had one of the legendary C65 prototype machines. Remembering how much he loved programming it at some point in time he starts recreating it in VHDL. With this courageous and ambitious step, he kicks off what later becomes the MEGA65 project.


Organizational structure behind the MEGA65 computer production

GMK Electronic Design design and manufacture high-end electronic modules and software applications for the professional use. GMK Electronic Design construct and manufacture the Cherry-MX-based MEGA65 keyboards.

Hintsteiner group produce industrial models, molds, carbon technology, prototypes and small series since 1981. Hintsteiner group build the MEGA65 cases for the developer versions as well as the final production line cases.

Trenz Electronic develop, manufacture, integrate and sell FPGA and SoC modules for business and science. Trenz Electronic design and build the MEGA65 mainboards and also assemble and sell the final machines.


An excerpt of the first MEGA65 press appearances


We are giving away the designs for free which take considerable time, effort and money to create.

While it is possible for anyone to download the sources for the FPGA, we are offering a service to keep you updated with the latest core files and infos. We ask for a donation of at least EUR 5 to help us provide this service and contribute to ongoing development. A project like this involves much greater costs than this, so larger donations are appreciated. Talk to us about special recognition for substantial donations.

Donate and get registered

Thank you very much! It's people like you that keep us going.

IMPORTANT: We are always looking for people willing to help in creating the best 8-bit computer ever!


You can send us a message via this form. Please note that unless you are press, you want to participate big time or have anything else of significance to tell us, we might not be able to answer. Our available time is being consumed on realising the MEGA65.