Hey all,

Got the LD bug again and picked up the above player for fair money, hadn't realised it was PAL only but hey ho.

I had to fix the tray as it had taken a good smack at some point and noticed the main board was pretty sparse, but saw it was obviously the same board for more expensive models with ntsc playback etc. Seems like its actually the cheap version of the s315, has anyone tried modifying these to have NTSC playback? It could be an IC is hard coded to ignore NTSC discs, which would not surprise me but just wondered if anyone else had the same idea to same me wasting time on it.

I kinda doubt it. There's probably a good reason why they didn't bother including analog PAL audio support for the early combis, despite it would've made sense because now people had all these old discs they couldn't play on their new machine.

If I were you, I'd probably just keep it as is and buy a second player for NTSC playback. At least you won't have to worry about the second machine having PAL support because it's bound to be better on your current one. I've certainly never heard of a PAL only player that couldn't play the old analog discs.

There's a CLD-S315 service manual in the LDDB collection, so you could compare that to your player and see what is and isn't populated (follow the N/XP output from the mechanism control IC on the main board for a start?). Presumably the S310 doesn't have the horrid standards converter on the PALB board, but you don't want that anyway.

One question is whether the firmware is the same for the S310 and S315. Looking at the pinout on page 46, the mode control IC has inputs to enable/disable various functions which are set using links on the FLKY board - and SW1 is "H: PAL model, L: dual model", which sounds hopeful. It would be interesting to see what it does with an NTSC disc with that link in each position...

Yeah I downloaded that and have been pouring over it. I hadn't got to the mode control IC so that's very hopeful. It doesn't look like there's anything too complex to add to N/XP path (page 22) to facilitate ntsc playback if that's the case. If it works I'll report back with a little parts list/guide.

I'd imagine most of the missing features can be added this way aside from dual side play obviously.

Try engaging test mode? Some NTSC players will play through at least some of a digital sound PAL disk, badly of course... and it's quite possible the CLD-S310S has a dual-standard TBC so it might actually play well.

Gotta imagine it's nigh impossible to mod a PAL LD player to play NTSC and vice versa. Don't they spin the discs at different speeds?

I thought of this as well, but I'm pretty sure the spindle motor speed is determined by a circuit rather than the motor itself, which again relates to altering the circuit boards.

I saw someone online claimed to convert an X9 for PAL playback.

Good luck!

Yeah. You can’t let yourself confuse the nature of NTSC/PAL with the way Region or DVD Macrovision works. An NTSC player isn’t “locked out” from playing PAL. It literally can’t do it, and yeah disc speed is part of it. I think most of the digital field buffer and comb filters and overlay generators are all region specific too.

The legacy that defines all of this is the frequency of the mains voltage. That determined the refresh rate of TV when it was invented, which meant that 50hz countries and 60hz countries would have different screen refresh rates, therefore one had more resolution, etc. Before quartz tuning the only clock most electronics had was the AC frequency.

A CAV disc is one lap per field, therefore frame rate determines RPM.

Like you zeta I think this is very unlikely. unless the designs are so 'open plan' that the 310 is so redundant to the 315 that just adding the components and a few extras could do it....

The schematic shows it's entirely possible, trivial even. A jumper setting enables it and adding a handful of components makes it work. It's right there in the service manual.

So a proof of concept. This is with just the jumpers set to dual ntsc/pal playback.



It plays!

As expected, the picture is black and white and the speed is in fact a bit slower than it should be. This is where adding the ntsc timing circuits will give proper playback. Like I say, it's a handful of components and should result in a pretty nicely priced dual system player.