Reminiscing: 8-Bit Atari Games Resources
Try the following for many 8-Bit Atari links:
More Reminiscing:
Atari Fonts For The Mac!
Here's the original character set for Atari 8-bit computers, which I transformed into a font for the Macintosh. All 255 characters are present (there was no character at $9B; it was an End Of Line) although not all them can be accessed on the Mac.

I also include an inverse version for easier access to these characters, as well as Graphics 1 versions of each:

Download Atari8Bit Screen Fonts (freeware).