Originally posted by fiath
OS? What does the A1 OS have to do with the classic Amiga's OS? Don't get me wrong, that is a serious question. Severin?
OS4 is a PPC rewrite in C of OS3.9 with all the chipset dependancies, bcpl, old cock ups etc. removed and new features added to bring it upto date. go to the Features List
and have a browse, also read some of the publically available CAM articles here.
Amiga Inc. supplied Hyperion with the source for the previous OS versions so It is a legitimate update to 3.9 based on the previous source, unlike MorphOS which is written to look like AmigaOS but as they didn't have access to the previous source is going to do things differently and could lead to incompatabilities.