CED VideoDisc and Player Discussion

[Spirantho]

Hi everybody,

As I've got 50 PAL CEDs and only one NTSC CED (but a very important one - The Beatles' "Let It Be") - I've been wondering how hard it would be to convert a PAL CED player (obviously mine's the standard Hitachi jobby, still working fine after 24 years)?

Does anyone have schematics for the PAL version of this machine and the NTSC version?

It should - in theory - just be a matter of timing as the colour encoding is I presume on the disc itself, so I'd just need to tell my CED player that the signal is at 60Hz, not 50Hz like PAL. I do wonder how it would cope with having the smaller resolution though (480 lines instead of 576 or whatever)... comparing schematics between the two versions may help!

Does anyone have any advice? It'd be great to be able to switch a switch somewhere and alternate between PAL and NTSC, and a simple electronic circuit could do that. It quite possibly only needs a tweak to a few resistors and maybe a timing crystal somewhere.
_________________
Ian Gledhill
IanG@--remove this--amiganet.org (remove -- to --)

[cedmagic]

This mod would actually be quite a bit more complicated than one might think. NTSC discs spin at 450 RPM while their PAL counterparts spin at 375 RPM, so the PAL turntable would have to spin at the higher rate before any decipherable signal could be recovered from the disc.

But the main problem would be to get that signal through the pickup arm. NTSC players use 910 MHz resonators, while PAL players use 890 MHz resonators. The resonator assembly was custom-manufactured for CED players, so it's not a simple item to swap out.

This is why I think having both an NTSC and a PAL player is the best way to deal with the need to be able to play both disc formats:

http://www.cedmagic.com/misc/ntsc-pal/ntsc-pal.html

--Tom Howe