Author Topic: Getting 60hz from PAL TG (and can anyone tell me what's in the US model?)  (Read 272 times)

pcenginesales

  • Jr. Member
  • **
  • Posts: 99
This is nuts.

Tried to replace the crappy PAL crystal in this, result: NTSC 50Hz video, console still clocked at 50Hz. Pulled up pin 10 of the processor (OSC input as stated here http://www.archaicpixels.com/index.php/HuC6280) wired the output of the 21.44727mhz crystal to that, still the console runs at 50Hz (what the hell?)

I completely turned the 50Hz crystal OFF as well as the adjacent crystal (I removed a jumper giving power to the whole circuit they were involved in.)

There's a chip taking input off the crystal and it appears to be what's giving the signal for the output video (well obviously.) And it's a chip that's definitely not in the original PC Engine. It appears to be a Z80 variant? Marked PCZ80-119. If it's a processor it could be taking over operations from the HuC6280. As giving the HuC6280 the correct crystal for 60Hz is NOT speeding up the system, it appears this PCZ80 chip is somehow forcing the whole board into 50Hz. The only thing that forcing a 60Hz crystal does, is turn the video colour encoding to NTSC. The output of the new crystal is fed to both this weird new chip AND the HuC6280. It does nothing to help.

Can anyone tell me if this chip is in the original TG-16? And the crystals, what are they and what do their output pins go into? What pin of PCZ80-119 does pin 8 of the D74HCU04 go into (if present?)

SOMEBODY TELL ME WHY THIS IS HAPPENING IT'S DRIVING ME NUTS. 50HZ MUST NOT BE ALLOWED.
www.retro-access.com - Modded consoles and SCART cables for retro consoles and computers. We ship worldwide.