open 8-bit computer
MEGA65 is an open-source new and open C65-like computer.
Hardware designs and software are open-source (LGPL).

Build the hardware at home or get it from us.
Enhance it yourself or together with the community.


An image says more than a thousand words so here are some random impressions from the MEGA65. They will be updated from time to time as the project proceeds.

Get MEGA65

MEGA65 is more than a retro computer, it is the 21st century realization of the C65 heritage. It is a complete 8-bit computer running around 50x faster than a C64 while being highly compatible. HD output, SD card support, Ethernet, extended memory and other features increase the fun without spoiling the 8-bit feel. We are giving away the designs for free which take considerable time, effort and money to create.

Download latest Bitstream

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

Passwords for the download are sent to registered email addresses on each update. We are manually sending out those passwords so please give us a day to do so.


Videos showing the MEGA65 computer in action, how to use and how to develop software for it. These videos are subject to change as the project evolves.

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.

CPU48MHz 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, with 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).
SpeedSynthmark64 score: 44.5x (C64 = 1x). Bouldermark score: 29,970 (C64 = 313).
DMAC65 DMAgic compatible DMA controller. Fills at 48MB/sec, copies at 24MB/sec, swaps at 12MB/sec.
Video ControllerVIC-IV advanced rasterised video controller, like the VIC-II and VIC-III no framebuffer. Native resolution 1920x1200 (192MHz 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 1920x1200 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 output 12-bit (4,096 colours). The planned DVI/HDMI output will support 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.
SoundDual soft-SIDs + dual 8-bit DACs.
RAM128KB RAM visible to VIC-IV, 32KB colour RAM visible to VIC-IV, 128KB ROM/RAM. 128MB of (extended) DDR2 RAM being worked on to be made accessible.
MediaD81 disk images from SD card (native VFAT32 file system support coming soon). Real 3.5" floppy drive support pLanned. Standard loading speed without fast loader ~20KB second. Loading speed direct from SD card 300 - 3000KB/second (1200 - 12000 blocks per second), depending on SD card.
OutputsJoystick ports 1 and 2 (9-Pin Atari Standard), VGA, 10/100mbit Ethernet,Mono Audio (Stereo soon), USB, Micro USB. Planned: HDMI, analog video, extension port, maybe external floppy.
InputsUSB (supports PC keyboards and adaptor cards), Micro USB, Ethernet, Micro SD slot, and coming soon: 3D accelerometer, on-board microphone and thermometer.
Operating SystemMEGA-OS all-in-one hypervisor and compat operating system, including integrated freezer and task switcher, VFAT32 file system driver and inter-process communications.
Form factorC65-like all-in-one. A laptop form is planned for a future release. Full-height 19" rack option extra.
Supported FGPAsNexys4DDR (and soon) Nexys4PSRAM. These boards include a Xilinx Artix7 100T FPGA, which is a high-performance FPGA, much faster and larger than the Spartan FPGAs used in other retro computing projects. Unfortunately the old Spartan FPGA boards cannot run the MEGA65 core.
Development optionsRight 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. For the future: 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).
MilestonesReached: the computer is fully operational as a stand alone machine. We are now adding bitplanes, extended Hypervisor and more DOS.
  • The MEGA65 computer is expected to be ready for sale in third quarter of 2016. However you can always start playing with and programming MEGA65 software on a NEXYS4 DDR board with the latest bitstream (download here). A tutorial on how to setup up everything is available here.
  • Contact

    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.