1. ATI Extended 8514/A mode may not use bit 5 of ATI reg 0xb0 sometimes but at the same time it won't use the standard VGA way of setting up 256+ colors, therefore, in the VGA DAC writes, use standard VGA way to revert to VGA mode in the writes instead of relying on bit 5 of ATI reg 0xb0 being enabled/disabled there. Fixes mode switches in VLB/PCI configurations using Windows 9x and possibly other stuff, ISA is unaffected and still works fine.
2. Added more logs and and remove/set I/O handlers correctly for the PCI side.
Mark the ATI extended 8514/A mode accordingly (that is, if bit 5 of ATI reg 0xb0 and using ATI extended ports at the same time). Fixes wrong colors in some instances using standard IBM 8514/A drivers on Mach32.
1. Added the missing call to mach32_updatemapping from port 0x3CF through its index 6.
2. If the accelerator DAC is active and the extended 256 color bit is on too then enable 8514/A mode when needed, otherwise it's VGA mode or decided by the passthrough/clock selection ports.
3. VGA DAC reads are redirected to the 8514/A DAC reads only when 8514/A mode is on.
1. vga_on global variable removed, as it didn't play well with 2 subsystems at once (8514/A and XGA both enabled).
2. Emulate the Foreground/Background Color aliases of PIX_TRANS properly when not executing a command.
3. Voodoo 3D override now works properly (again) with Mach32 PCI cards and others by turning the 8514/A timer off and on accordingly.
1. Simplified 4bpp rendering mode.
2. Implement CRTC31 bit 0 functionality which enables/disables the vendor banks. Fixes Diamond Stealth 64 964 VRAM (VLB/PCI) detection on NT 3.1 (and possibly other cards) while keeping NT 3.1 347.1's full screen Command Prompt test normal without garbage using the 911/924 chips.
