!!!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) %%prettify {{{ ? PEEK(43234) }}} /% and then press RETURN. The computer will give you an result. ||Result||BASIC||Comment |162|Revision A|First Atari BASIC cartridge, 8K ROM. |96|Revision B|Found built-in on the 600XL and early 800XLs. Never supplied on cartridges. |234|Revision C|Found on later 800XLs, the 800XLF, XEGS and all XE computers. Limited cartridge production run. For an description of the known errors, see the Wikipedia Article on ATARI Basic: [https://en.wikipedia.org/wiki/Atari_BASIC] See also [OS Versions]