F4/FMPAC Light Combo Board project

Page 15/15
8 | 9 | 10 | 11 | 12 | 13 | 14 |

By Alexey

Guardian (1752)

Alexey's picture

24-09-2017, 21:58

The board version 1.2 is basically the same as the last version in our repository. But your version doesn't have the internal/external bios switch. So you should use the "internal.rom" 16kb bios file for the EPROM. If you are using the 27c256 EPROM, append the bios file to its end to get a 32kb image consisting of 2 identical 16kb parts.

By OeiOeiVogeltje

Paragon (1209)

OeiOeiVogeltje's picture

24-09-2017, 22:02

thank you for your swift answer

now let me find that repository for that parts list..

By Alexey

Guardian (1752)

Alexey's picture

02-12-2018, 02:37

I decided to revisit this project and make some improvements. Now there will be options to connect the audio output directly to the internal MSX's amplifier and also to properly connect it to the internal slot where another audio hardware might be present. In addition, the board now has properly routed power and ground as well as the amplifier. The logic chips have blocking capacitors now. In addition, there will be an optional ground separation between the analogue and the digital parts of the board. And finally the schematics has been fully re-drawn.

The board and the schematics can be seen below.

I have ordered 10 board to test the improved design. If that works well, I will update the files in our repository.

By alexito

Master (219)

alexito's picture

02-12-2018, 20:39

I would like to see if this new design fix the problem with my Yamaha CX7M/YIS604 + FmPac Combo Ver 1.2 + MFRSCC+SD + SKY JAGUAR (DUAL PSG VERSION) Where the MFRSCC+SD EXTRA PSG never get ACTIVE. That problem not happen with my FmPac Combo ver 1.0 + the same setup from above.

By Alexey

Guardian (1752)

Alexey's picture

04-12-2018, 16:31

There are no major differences between 1.0 and 1.2 versions of the board except for the better layout that reduces the digital noise (in the latest versions). If you figure this out somehow, please let us know.

Page 15/15
8 | 9 | 10 | 11 | 12 | 13 | 14 |
My MSX profile