Yamaha V9958
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The Yamaha V9958[1][2][3] is a Video Display Processor used in the MSX2+[4] and MSX turbo R series of home computers, as the successor to the Yamaha V9938 used in the MSX2. The main new features are three graphical YJK[5][6][7] modes with up to 19268 colors and horizontal scrolling registers. The V9958 was not as widely adopted as the V9938.
Specifications
[edit]- Video RAM: 128 KB + 64 KB of expanded VRAM
- Text modes: 80 × 24 and 32 × 24
- Resolution: 512 × 212 (4 or 16 colors out of 512) and 256 × 212 (16, 256, 12499 or 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
Feature changes from the V9938
[edit]The following features were added to or removed from the Yamaha V9938 specifications:
- Added horizontal scrolling registers
- Added YJK graphics modes (similar to YUV):
- G7 + YJK + YAE: 256 x 212, 12499 colors + 16 color palette
- G7 + YJK: 256 × 212, 19268 colors
- Added the ability to execute hardware accelerated commands in non-bitmap screen modes
- Removed lightpen and mouse functions
- Removed composite video output function
MSX-specific terminology
[edit]On MSX, the screen modes are often referred to by their assigned number in MSX BASIC. 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 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 |
References
[edit]- ^ IC Master. United Technical Publications. 2001.
- ^ Martín Sesma, Sergio (2016-10-03). Arqueología informática: los ordenadores MSX en los inicios de la microinformática doméstica (Proyecto/Trabajo fin de carrera/grado thesis). Universitat Politècnica de València.
- ^ Redazione (2008-10-20). "MSX - Vari Costruttori- 1983". CyberLudus.com (in Italian). Retrieved 2022-11-13.
- ^ Alex, Wulms (1995). "Schermen op MSX - De 2+ schermen" (PDF). MSX Computer & Club Magazine (72).
- ^ MSX Licensing Corporation (2022). "The YJK screen modes". MSX Assembly Page.
- ^ Niemietz, Ricardo Cancho (2014). Issues on YJK colour model implemented in Yamaha V9958 VDP chip (PDF).
- ^ "VCFe Vortrag vom 2016.04.30 - Homecomputer und Spielkonsolen - Videoarchitekturen als visuelles Medium". neil.franklin.ch. Retrieved 2022-11-13.