1.5 KiB
VBMP
BMP Viewer for the Apple II
Introduction
This project is based on the work of Arnaud Cocquière and his hommage to Steve Jobs.
http://www.ctrl-pomme-reset.fr/2011/10/11/hommage/
Unlike most images shown on the Apple II, the image displayed is actually a BMP file without additional conversion. The disk includes the sources for the BMP viewer, so I decided to study it and learn a bit of 6502 assembly and graphics programming on the Apple II. Since my Apple IIc supports DHGR graphics I started playing with it to add support to 16 color BMPs and monochrome pictures in Double High-Res. I thought this could be useful for someone else so I asked Arnaud for permission to publish it in GitHub.
Usage
The code uses the Merlin Assembler syntax. Just load it in Merlin on the Apple II and it should compile without problems. To load BMPs in the DSK Image I recommend Apple Commander, but Cider Press might do as well. Just import the BMP as a Raw binary file. Using Applesoft you can load the image with the following commands BLOAD IMAGE.BMP,A$4000 BRUN DISPLAY
Supported formats
The viewer supports BMP Images with the following resolutions and color depths
- Monochrome (1bit color depth) 280 x 192 px
- Monochrome (1bit color depth) 560 x 192 px
- 16 Color (4bit color depth) 140 x 192 px The formats are automatically detected based on the horizontal resolution. Using different formats as the ones listed may lead to unexpected results since the format check has been kept as simple as possible.