Some issues

[gyurco]

Hi!

I ported this core to MiST, and during the work I discovered some issues:

• The pixel clock is wrong, it should be 48/8, not 48/9 MHz:
  https://github.com/MiSTer-devel/Arcade-Galivan_MiSTer/blob/master/Arcade-Galivan.sv#L305
  Also the counter ranges are not correct, I think (I've used the ones from ArmedF instead).

• The FM chip clock should be 4 MHZ, not 6MHz:
  https://github.com/MiSTer-devel/Arcade-Galivan_MiSTer/blob/master/rtl/core.v#L359

• DACs are not connected, however they're used.

• MCPU's IRQ is wrongly reset by ACPU's signals:
  https://github.com/MiSTer-devel/Arcade-Galivan_MiSTer/blob/master/rtl/core.v#L64

• In Dangar, the ACPU's code is enabling the interrupts before switched to IM1 mode. But if open bus returns FF (RST 38h), then it works correctly. I wonder is there any music in Dangar on MiSTer?

• The graphics machine is using too much logic, also tilemap layers are usually not rendering into line buffers, but they're working on-the-fly.

Sorry, no pull request, as I don't have a MiSTer to test.
You can find my changes at:
https://github.com/gyurco/Mist_FPGA/tree/master/Arcade_MiST/Nichibutsu%20Galivan%20Hardware

[Pierco]

Thank you for the comments, will fix in the coming days!

[Pierco]

• The pixel clock is wrong, it should be 48/8, not 48/9 MHz: fixed ✔️
• Also the counter ranges are not correct: not fixed yet ❌
• The FM chip clock should be 4 MHZ, not 6MHz: fixed ✔️
• DACs are not connected, however they're used: fixed ✔️
• MCPU's IRQ is wrongly reset by ACPU's signals: fixed ✔️
• The graphics machine is using too much logic: not fixed yet ❌

I'm closing the issue. I will try to fix the rendering logic and counters later. Thank you so much for your help!!