Bochs VBE Extensions: Difference between revisions
Jump to navigation
Jump to search
→Programming the BGA
| [unchecked revision] | [unchecked revision] |
(Added getcaps stuff based on bochs code search) |
|||
Line 95:
Based on source code examination for Bochs (iodev/vga.cc) setting VBE_DISPI_GETCAPS in VBE_DISPI_INDEX_ENABLE makes the VBE_DISPI_INDEX_ (XRES / YRES / BPP) fields return their maximum values when read instead of the current values.
=== 8-bit DAC ===
The default palette DAC is a 3x6 bit dac; it returns a value between 0 and 63 for each color. Setting the VBE_DISPI_8BIT_DAC bit in VBE_DISPI_INDEX_ENABLE changes this to a 3x8 bit dac and converts the palette to the appropriate values. Resetting the bit moves them back again.
=== Miscellaneous ===
[TODO: check and describe VBE_DISPI_INDEX_VIRT_WIDTH/HEIGHT, VBE_DISPI_INDEX_X/Y_OFFSET
=== Example code ===
| |||