How to find the OS Version of your computer#

Atari ROM Checker by JAC!#

For ATARI 400 and ATARI 800 Computers#

In Atari BASIC type the following command if you have an 400/800
PRINT PEEK(65528) 
and press the RETURN key

ValueOS VersionCRC 32MD5ROMs
255First 800 OS NTSC ; please further see Rarity 10??we are still searching for this. Please help us ;-)
221400/800 OS Rev. A NTSCc1b3bb02a3c1585b5d19719f8acfa2b093bea75fCO12499A, CO14599A, CO12399B
214400/800 OS Rev. A PAL72b3fed4eb1f32f5d9f382db1bbfb8d7f9cb343aCO15199, CO15299, CO12399B
243400/800 OS Rev. B NTSC0e86d61d4177f386a3bac989a981d3fe3388cb6cCO12499B, CO14599B, 12399B
34400/800 OS Rev. B PAL; please further see Rarity 100c913dfc89d5e5f4713267667ab713449944f8a9 Kr0tki-Versionwe are still searching for this. Please help us ;-)

For ATARI XL and XE Computers#

If you have an XL or XE Computer, type
and press the RETURN key

10XL/XE OS Rev 10
11XL/XE OS Rev 11
1XL/XE OS Rev 1
2XL/XE OS Rev 2
3XL/XE OS Rev 3
59XL/XE OS Rev 3B (Arabic)
4XL/XE OS Rev 4

see also How to find the revision number of Atari Basic