Summary

1. Rewritten Sierra SC1502x RAMDAC code to match the manual, allowing proper BPP selection on cards which use it.
2. Added a reference clock variable for cards which have a different default one (ELSA cards namely) on the ICD2061 code.
3. Reorganized RAMDAC selection in the S3 code.
4. Added more ELSA Winner cards based on the 928 chip (ELSA Winner 2000 ISA, 1000 VLB and 1000 PCI based on 928PCI).
5. The horizontal override is now also enabled for ELSA Winner 1000 (928 VLB and PCI) cards with 32bpp set, to avoid wrong horizontal displays.
6. LFB in PCI mode doesn't have the same limitations as on VLB or ISA.
7. Added more hdisp adjustments for the Elsa cards.
8. Mono patterns are now more correct in ROPBLT acceleration (command 14), fixes blackness in some instances of Win95 (matching the 968 manual).
9. Minor cleanup on the accel registers.

Checklist

• Closes #xxx
• I have discussed this with core contributors already
• This pull request requires changes to the ROM set
  • I have opened a roms pull request - Added more ELSA Winner S3 cards. roms#376

References

Provide links to datasheets or other documentation that helped you implement this pull request.