Yamaha V9958
This page was last modified 22:39, 12 July 2017 by ApolloBoy. Based on work by Mars2000you and Gdx and others.
Yamaha V9958

The Yamaha V9958 is a Video Display Processor (VDP) used in MSX2+ and MSX Turbo R computers. A few MSX2 computers have also this VDP, but the MSX2+ screen modes are not accessible in MSX-BASIC. The V9958 is the successor of the Yamaha V9938 that was used in the MSX2. It is generally considered to be a minor upgrade of the V9938, with three YJK graphic modes (with up to 19,268 colors) and horizontal scrolling registers.

Contents

Specifications

  • VRAM: 128 KB + 64 KB of expanded VRAM
  • Text modes: 80 x 24 and 32 x 24
  • Resolution: 512 x 212 (16 colors out of 512) and 256 x 212 (19268 colors)
  • Sprites: 32, 16 colors, max 8 per horizontal line
  • Hardware acceleration for copy, line, fill, etc.
  • Interlacing to double vertical resolution
  • Horizontal and vertical scroll registers

Detailed specifications

On top of the Yamaha V9938 specifications, the V9958 added:

  • Horizontal scrolling registers
  • YJK graphic modes (similar to YUV)
    • G7 + YJK + YAE: 256 x 212, 12499 colors + 16 color palette
    • G7 + YJK: 256 x 212, 19268 colors
  • Ability to execute hardware accelerated commands in non-bitmap screen modes
  • Packaging: 64 pin "Shrink" DIP (same as V9938)

Links

MSX screen modes

On the MSX, the documented screen modes are often referred to by their assigned number in MSX-BASIC (see SCREEN and CALL KANJI pages for more info). This mapping is as follows:

Basic mode VDP mode MSX system
Screen 0 (width 40) T1 MSX 1
Screen 0 (width 80) T2 MSX 2
Screen 1 G1 MSX 1
Screen 2 G2 MSX 1
Screen 3 MC MSX 1
Screen 4 G3 MSX 2
Screen 5 G4 MSX 2
Screen 6 G5 MSX 2
Screen 7 G6 MSX 2
Screen 8 G7 MSX 2
Screen 9 G5 or G4 used in text mode Korean MSX 2
Screen 10 G7 with YJK and YAE MSX 2+ and tR
Screen 11 G7 with YJK and YAE MSX 2+ and tR
Screen 12 G7 with YJK MSX 2+ and tR
Kanji0 G4 or G6 used in text mode MSX 2+ and tR
Kanji1 G4 or G6 used in text mode MSX 2+ and tR
Kanji2 G4 or G6 used in text mode MSX 2+ and tR
Kanji3 G4 or G6 used in text mode MSX 2+ and tR