Hi all, As the CRT screens with analog video input are being replaced with flat panels that take digital signals such as HDMI, it would seem to make sense to design a converter based on open hardware. Before you exclaim that such converters exist or that some screens can accept analog video from the C64, here are two counterexamples. First example: About a dozen years ago, I tried to be future-proof and bought a cheap Chinese converter that outputs analog VGA (which is now gone). The VGA output signal is so bad quality that my current flat panel screen refuses to display it. It only works with a CRT VGA monitor, and even then in a very noisy way. I would expect currently available analog-to-HDMI converters to be a hit-or-miss, it either works, does not work, or works badly. I would guess that HDMI is here to stay for a while, being based on DVI and DisplayPort, and the standard being updated constantly. Second example: Some flat screens are picky and do not display anything. Here is an example of that: http://www.raphnet.net/divers/commodore64/index_en.php#1 Another example is my TV, which refuses to display a picture from my NTSC Vic-20 board, and refuses to support separated luma and chroma (Y/C aka S-video). I see a few possible approaches to this problem. Maybe the trickiest one would be to adjust the signal in the analog domain, so that any equipment would accept it. This would be tricky, because most Commodore home computers do not output properly interlaced video. The NTSC VIC-I chip is the only known exception to me: an interlaced mode can be enabled on it. The most future-proof way might be to use a generic A/D converter and a fast enough FPGA. A more practical way could be to use a special video A/D converter chip, such as this one: http://www.analog.com/static/imported-files/data_sheets/ADV7181C.pdf This chip is used on the MilkyMist One: http://m-labs.hk/m1.html It is open hardware, with FPGA and microcontroller code available at https://github.com/m-labs/milkymist and the schematic diagrams etc. at the following locations: http://en.qi-hardware.com/wiki/Milkymist_One_Schematic_Change_History http://en.qi-hardware.com/wiki/Milkymist_One_R4_BOM http://downloads.qi-hardware.com/hardware/milkymist_one/sch/20120710/Milkymist%2 +0One%20R4%20-%2020120710.pdf Does anyone happen to have experience of such A/D converter chips, or connecting Commodore hardware to the video inputs of the MilkyMist One? The ADV7181C claims to support almost anything: PAL, SECAM, NTSC, SCART Fast-blank RGB, and some stuff in the VBI, such as wide-screen signalling and teletext (Ceefax), and various versions of the MacroVision protection. The challenge would be to capture the output into a frame buffer and output it via HDMI. We would also require a separate A/D converter for the audio. A bonus would be to make it so low-power that it would work with the small power supply that is available on the HDMI jack. Marko Message was sent through the cbm-hackers mailing listReceived on 2015-01-03 22:00:03
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