To find the version of GS/OS and associated files installed on a particular disk, hold the space bar down during startup. This presents a text screen with the version numbers displayed.
The version number displayed at the top center of this screen correlates as follows:
On-Screen
Version # Date GS/OS Version (as Labeled on Disk)
--------- --------- ----------------------------------
4.0 Aug 18 88 GS/OS 4.0
3.00 (or lower) May 30 89 GS/OS 5.0
3.02 Dec 15 89 GS/OS 5.0.2
3.03 Aug 20 90 GS/OS 5.0.4
4.01 Mar 04 92 GS/OS 6.0
- On-screen version numbers lower than 3.00 indicate GS/OS 4.0
- ProDOS 16 displays a startup screen with "PRODOS 16" on it
- System Disk 3.2 indicates ProDOS 16 v1.6
- System Disk 3.1 indicates ProDOS 16 v1.3.