Legendary Commodore 64 Gets A True Full HD HDMI Upgrade For A Retro Reboot
If you've ever played with an original 8-bit computer—a Commodore, an Atari 400/800, or anything else of that vintage—you already know that getting clean video output can be a terrific struggle. These systems were primarily built to output a video signal using radio frequency (RF) output, not unlike a regular TV antenna, and require mods to even get clean RGB video output, much less anything digital.
There have already been a few HDMI mods for the Commodore 64, but none of them are as complete as the new HD-64 by SideProjectsLab (SPL). This modular upgrade for your classic computer replaces the entire OEM RF modulator daughterboard with one that sports a Xilinx Spartan-7 FPGA. This chip implements the entire output stage of the Commodore 64 by sniffing the C64's memory bus and reconstructing the video signal through emulation. Finally, this clean digital picture is upscaled to 1920x1080 full HD, merged with digitized audio output from the Commodore's SID chip, and output via micro-HDMI.
Critically, the original VIC-II chip remains in place as the HD-64 doesn't replace it, which retains full compatibility with all software, at least in theory. But the HD-64 does do a couple of things that other HDMI mods have not done. Compared to the popular Lumacode mod, the HD-64 is fully internal and arguably fully hardware-based—depending on how you view FPGA emulation. The point is that it doesn't require any additional software, although you CAN use software to configure the HD-64 with a few options, including palette customization, optional scanline and blur filters, and wide-screen stretching.
Compared to the more recent VIC-II Kawari, the HD-64 outputs in higher resolution, and it also includes audio on the HDMI connection—stereo, even, if you have a dual SID mod. This makes it uniquely suited to Commodore 64 consoles used in the living room with larger TVs, as many modern TVs no longer support "DVI style" connections where an HDMI plug is used for video along with an analog connection for audio. Of course, for more conventional computer-style use, this isn't a concern, and the Kawari, being a full VIC-II replacement, supports some extended features that the HD-64 doesn't, such as the ability to simulate different VIC-II revisions and do freeze-frame debugging.
The HD-64 is also more expensive than the VIC-II Kawari, coming in at around $125 US versus the circa $85 of the older mod. Still, it has more advantages over the VIC-II Kawari than we've already mentioned. The HD-64 supports virtually all Commodore 64 models including NTSC "shortboard" hardware, and it's also capable of automatic NTSC/PAL detection. Notably, analog video is still available on the original 8-pin DIN connector, so you can use composite or S-Video on real CRTs, and the HD-64 even corrects the S-Video voltage so that it doesn't look so dim.
Technically, SPL revealed the HD-64 back in January with the video above, but the news right now is that a new batch of boards has become available for sale. If you're keen to upgrade your C64 with a modern display connection, you can hit up Retro8BitShop or Retro Updates, both of which are selling the SPL HD-64 for €109.
