Commodore 64 gets a true Full-HD HDMI plus stereo sound daughterboard

Commodore 64 devotee Side Projects Lab has released a video teaser showcasing a "true Full-HD HDMI" adaptor for the iconic 8-bit home computer. Apparently, the development of this slick HDMI solution with stereo sound routed through the HDMI cable has taken a full year. If you are interested in the new HD-64, there is still some wait time though, as the first production batch won't be ready until later in Q1.

Side Projects Lab (SPL) thanks fellow C64 video aficionado c0pperdragon early on in the video, as you will see the new FHD HDMI adaptor is built on that impressive prior work (which featured RCA YPbPr video outputs). SPL bought c0pperdragon's drop-in RF modulator replacement daughterboard about a year ago and while pleased with the RCA video output, felt the desire for a crisp HDMI option, with 1080p upscaling, and stereo audio via a single cable.

The C64's VIC-II graphics chip doesn't have a digital video output, and its analog video "is often noisy and distorted beyond repair," according to SPL. In other words, this is a GIGO situation that can't be fixed with filters or other image processing tech - after the fact. c0pperdragon knew this too, so made an interleaver that grabbed digital video signals before they got to the VIC-II graphics chip.

However, SPL wanted to output to the ubiquitous HDMI connector at true FHD. Moreover, for the utmost convenience, they decided to direct SID audio through the same HDMI port. This became the HD-64 project, now claimed to be "the definitive HDMI solution for the Commodore 64." You can read through the above-linked GitHub pages for deeper details on how all the necessary video frame and audio data was acquired and fed to a VIC-II emulator in the FPGA – with just <1ms latency added.

As well as its thoroughly modern convenience, the new HD-64 comes with some retro gaming niceties like scanlines, anti-aliasing, color tweaking, and aspect ratio adjustments in C64 software. Moreover, the developer promises to add adjustable overscan support in due course.

Pure retro vs modern convenience

Owning, cherishing, and making use of old computers comes with a convenience penalty, and that notion applies to the 1982 classic Commodore 64 as much as its contemporaries and 16-bit successors. This HDMI solution makes using the C64 with modern HDMI TVs and monitors so simple.

Ancient supporting hardware and peripherals like CRTs, tapes, floppies, and so on are simply wearing out or breaking with less and less hope for repair or service as we emerge halfway through the 2020s. Meanwhile, convenient and accurate emulation software for PCs, Macs, and consoles continues to be refined. This seems to be why Retro gamers have recently been observed to be backing away from overtly purist tendencies.