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.
Result | Revision of 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