Hi, nesdev. This is translated emu-land topic
http://www.emu-land.net/forum/index.php ... 737.0.html
HardWareMan wrote:
I've made PCB for MicroGenius IQ-501 box (Dendy Classic) by Eugene.S request.
Revision 1:
Wise way for power rails, fill maximum of GND polygon, power button before 7805 and diode bridge at input (wrong polarity protection).
Analog and digital power rails divided by inductors right after 7805.
All analog part have GND polygon at other side of PCB.
This is video recordings via TV tuner (composite at left side and S-Vide at right):
Sound test is here.
Solstice spectrogram:
Summary: It have 50dB SNR on bright video, but when you're playing soundtests on black screen, SNR is lower than 60dB.
Bugs: I forgot about "Eject" mechanism and LED header. Forgot NMI pull-up.
Revision 2:
Almost all bugs are fixed. I forgot about 220k resistor between collector/base of VT5.
Revision 2 have 2 XTALs! You can select CPU and PPU clock separately!
So, you can customize your system as PAL, NTSC, or Hybrid (dendy-mode).
As a bonus, you can make this "Frankenstein":
Ricoh RP2A03 clocked by the NTSC XTAL and UA6538 clocked by PAL XTAL,
which is Dendy, but with absolutely accurate sound pitch and duty cycles (and broken CPU/PPU=1/3 ratio)
RP2A03E+UA6538 Solstice spectrogram:
BTW, 6527P on the 21 Mhz NTSC XTAL works funny and have 1.43 Mhz clock speed
Here is source files (gerbers), if you want to make your own exemplar on the factory.
I've use http://dirtypcbs.com/
It's revision 2.1, where all bugs are fixed! Enjoy!
http://www.emu-land.net/forum/index.php ... 737.0.html
HardWareMan wrote:
I've made PCB for MicroGenius IQ-501 box (Dendy Classic) by Eugene.S request.
Revision 1:
Wise way for power rails, fill maximum of GND polygon, power button before 7805 and diode bridge at input (wrong polarity protection).
Analog and digital power rails divided by inductors right after 7805.
All analog part have GND polygon at other side of PCB.
This is video recordings via TV tuner (composite at left side and S-Vide at right):
Sound test is here.
Solstice spectrogram:
Summary: It have 50dB SNR on bright video, but when you're playing soundtests on black screen, SNR is lower than 60dB.
Bugs: I forgot about "Eject" mechanism and LED header. Forgot NMI pull-up.
Revision 2:
Almost all bugs are fixed. I forgot about 220k resistor between collector/base of VT5.
Revision 2 have 2 XTALs! You can select CPU and PPU clock separately!
So, you can customize your system as PAL, NTSC, or Hybrid (dendy-mode).
As a bonus, you can make this "Frankenstein":
Ricoh RP2A03 clocked by the NTSC XTAL and UA6538 clocked by PAL XTAL,
which is Dendy, but with absolutely accurate sound pitch and duty cycles (and broken CPU/PPU=1/3 ratio)
RP2A03E+UA6538 Solstice spectrogram:
BTW, 6527P on the 21 Mhz NTSC XTAL works funny and have 1.43 Mhz clock speed
Here is source files (gerbers), if you want to make your own exemplar on the factory.
I've use http://dirtypcbs.com/
It's revision 2.1, where all bugs are fixed! Enjoy!