GS Frame and Z Buffers

4Ch/4Dh FRAME_1/2

• 0-8 Base pointer in words/2048
• 16-21 Buffer width in pixels/64
• 24-29 Format
  • 00h=PSMCT32
  • 01h=PSMCT24
  • 02h=PSMCT16
  • 0Ah=PSMCT16S
  • 30h=PSMZ32
  • 31h=PSMZ24
  • 32h=PSMZ16
  • 3Ah=PSMZ16S
• 32-63 Framebuffer mask

Bits 32-63 prevent the specified bits in the framebuffer from being updated by the following formula:

final_color = (final_color & ~mask) | (frame_color & mask)

This mask is applied before format conversions, e.g., bit 63 of FRAME will affect bit 15 (alpha bit) of a 16-bit color.

4Eh/4Fh ZBUF_1/2

• 0-8 Base pointer in words/2048
• 24-27 Format
  • 00h=PSMZ32
  • 01h=PSMZ24
  • 02h=PSMZ16
  • 0Ah=PSMZ16S
• 32 Buffer mask (1=do not update zbuffer)

The zbuffer's width is the same as the framebuffer's, specified in FRAME.