Hmmm, I was gonna say YES to VCDs playing on ALL DVD players, but I guess if there is ONE somewhere, the answer is NO.
The PS2 is NOT a DVD player. It is a gaming device that is capable of playing DVD movies. Besides, they don't really exist anyway (vaporware), at least not in enough quantities to satisfy its customers.
Most standalone DVD players should be able to play VCDs. Whether or not the DVD player can play VCDs burned on CD-Rs and CD-RWs depends on the player, manufacturer, etc as Yuri noted above. Some specs will specifically note CD-R or CD-RW playback capability, but I have seen those disputed by people who by them and try them.
DVD-ROM drives should play VCDs and the only thing you need is the VCD software (or Quicktime 4.0).
VCDs will play in any CD-ROM drive (with VCD software), too.
However, most DVD players will NOT play Super VCDs.
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Dan
Michigan Lincoln & Continental Owners Club