OS Diffs Atari 800 <-> Atari XL/XE Series#

Answers-Tips-and-Relevant Information

by Paul Alhart

I really like my 1200XL, but at the same time I really hate having to use the TRANSLATOR to boot up certain software. What to do? I Translated the offending software to run on my system and filed my Translator Disk away in the back of a drawer somewhere.

You can do the same. In the beginning, Atari said, "If programmers use the PUBLISHED VECTORS into the Operating System (O/S), their programs will run on ANY 8-bit Atari Computer." (IF is such a big word.) To make a long story short, some programmers did not follow this rule, but to save a few bytes, jumped right into the O/S. This was fine before the XL/XE machines came along with a different O/S.

The published vectors are still the same as Atari promised, but they point to different locations in the O/S. The following list gives the published vector location and the vectors name followed by the ILLEGAL O/S entry points. If you find that a program Jumps to F3F6 to open the screen, (20 F6 F3) and you have an 800XL, change the code to (20 8E EF). Remember: Low byte/High byte.

I have found this to be the most common ILLEGAL jump. The next most common are the "K: Get/Put" calls. I spent many hours Peeking into my operating system with a lot of help from Compute's Mapping The Atari to come up with this list. It now saves me lots of time and hopefully will help you also. Note: Translated software will only run on the O/S that it has been translated for, so keep an original copy as back-up.