DSP2 Effective

Last Update: 2010/11/01 23:05 +0900

Summary

About DSP2 Gamepaks, Copyright Snes9x DSP Team 2003-2004. Maintained by Overload. (Added on May 03, 2004)

Anyway, this document is based on knowledge of DSP2 Gamepaks and published without its author's recommendation/permission. (Added on May 03, 2004)

Command 01H

DM will convert the packed-pixel bitmap image into bitplane image in tile unit.

There are 21 x 16 (336) tiles to be converted. Each tile has 8 x 8 and costs 32 bytes.

DM will totally send 10752 (32 * 336) bytes to DSP2 and receive 10752 bytes from DSP2.
Totally it transmits 21504 bytes per display image format conversion between console and DSP2.
This value is not actual due to overhead of command bytes.

Command 05H

Composite the two images into one.

This and later commands are invoked per scanline.

Command 06H

Make a mirror bitmap image.

Command 03H

Select a new color key.

Command 09H

Integer multiplication. Used to calculate the rendering offset position of opening door.

Input/Output Effect
0 * 36 = 0
22 * 36 = 792
44 * 36 = 1584
66 * 36 = 2376

Command 0DH

Image stretching.

Meaning Operation
Vertical stretching.

DM decides which scanlines are needed.

»
Horizontal stretching.

Op0D performs horizontal stretching per scanline.

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