How to find the revision number of Atari Basic#

With the BASIC cartridge put into your 400/800 or BASIC switched on, type (e.g. after the READY prompt)

PEEK(43234) 

and then press RETURN.

The computer will give you an result.

ResultRevision of BASICComment
162Revision Awas sold as cartridge for ATARI 400 and 800
96Revision Bbuilt into XL models (1200XL,600XL,800XL)
234Revision Cbuilt into XE models (65XE,130XE,800XE)