motherboard mod

[Cristian]

I found the following picture about a modified (or repaired?) motherboard.
I've already seen something like this, but I can't remember the reason of such modifications... any idea?

[mk79]

I think that was part of the US Version and maybe connected to the NTSC capability. But I might remember that wrong

[bwinkel67]

Yup, that's what my US version looks like. Not sure what all that is for.

[Dave]

It's Samsung's mod to buffer the 15 MHz clock signal.

[Cristian]

So it is the "official" mod to generate the NTSC signal. Could it easily be restored to PAL in your opinion?

[Dave]

It has nothing to do with NTSC. It simply improves the 15 MHz clock fed to the 8301.

The US QL has a JSU ROM which sets the NTSC bit in the 8301's register. This converts TV mode to NTSC with a lower resolution and repositioning of windows. Replacing it with a plan JS or Minerva ROM restores normal PAL resolution and fonts. If using the RGB socket, output will be completely standard. The modulator is an NTSC modulator. If you plan to use the UHF signal, it will not work correctly at PAL frame rates.

The QL itself works fine though.

[Cristian]

Thank you very much for your clarification Dave!