Thanks, Crazyc! I made some progress. Debugging is dead slow, plus i havent mastered palette and IRQ handling yet.

Some questions

How do i set up a second, independent palette for SCREEN 2?

Is there a way to speed up debugging under Visual Studio 2015 (i have quite a beefy laptop with a core I7 and an SSD, but it comes to a crawl with debug builds)...?

I added a macro statement for VSYNC
Code
MCFG_UPD7220_VSYNC_CALLBACK(DEVWRITELINE("upd7220", upd7220_device, ext_sync_w)))
... but don't know where to put the actual IRQ code:

(something like)
Code
if(m_GDC_MODE_REGISTER & GDC_MODE_ENABLE_VSYNC_IRQ)
	raise_8088_irq(IRQ_GRF_INTR_L);

[Linked Image from dl.dropboxusercontent.com]
(WIP: pacman ghosts on the right. No palette, no colors. Still some VRAM bugs)

Last edited by Bavarese; 09/14/16 09:08 AM.