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(Created page with "{{Infobox GB Homebrews |title=Space Invaders |image=spaceinvaderdemogb.png |description=Demonstrates how to use scan-line interrupt scrolling. |author=Jeff Frohwein |lastupdated=1997/10/26 |type=Samples |version=1.0 |format=DMG-ASM |license=Mixed |download=https://dlhb.gamebrew.org/gbhomebrews/spaceinvaderdemogb.7z |website=http://www.devrs.com/ |source=https://dlhb.gamebrew.org/gbhomebrews/spaceinvaderdemogb.7z |donation= }} {{#seo: |title= (Samples) - GameBrew |title_m...") |
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|type=Samples | |type=Samples | ||
|version=1.0 | |version=1.0 | ||
|license=Mixed | |license=Mixed | ||
|download=https://dlhb.gamebrew.org/gbhomebrews/ | |format=DMG (ASM) | ||
|download=https://dlhb.gamebrew.org/gbhomebrews/si.zip | |||
|website=http://www.devrs.com/ | |website=http://www.devrs.com/ | ||
|source=https://dlhb.gamebrew.org/gbhomebrews/ | |source=https://dlhb.gamebrew.org/gbhomebrews/si.zip | ||
}} | }} | ||
{{#seo: | {{#seo: | ||
|title= | |title=GameBrew | ||
|title_mode=append | |title_mode=append | ||
|image=spaceinvaderdemogb.png | |image=spaceinvaderdemogb.png | ||
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==External links== | ==External links== | ||
*Author's website - | *Author's website - http://www.devrs.com/ | ||
Latest revision as of 12:18, 2 August 2024
| Space Invaders | |
|---|---|
 | |
| General | |
| Author | Jeff Frohwein |
| Type | Samples |
| Version | 1.0 |
| License | Mixed |
| System | DMG (ASM) |
| Last Updated | 1997/10/26 |
| Links | |
| Download | |
| Website | |
| Source | |
This is a programming demo showcases how to implement games with more than 40 moving objects on the Game Boy, which typically supports only 40 sprites on screen simultaneously.
Using Space Invaders as an example, a quick assembly suggested that they use separate tiles for each invader to achieve smooth movement. However, this approach consumes significant ROM and valuable tiles. An alternative method involves dynamic tiles, but it still requires considerable ROM.
The demo code introduces another method for smooth scrolling by modifying the Background X scroll register on a line-by-line basis, based on the LYC scan interrupt. It interrupts at every scan line allowing the scroll register to be modified.
Note: This is currently not a working game. It only demonstrates a scrolling method.
Compatibility
The demo ROM code will work on the real Game Boy, VGB 1.0 or later, and possibly other emulators. It does not work on VGB 0.71 and possibly others.
External links
- Author's website - http://www.devrs.com/