https://archive.org/download/Basic_Programs_for_the_Atari_600XL_and_800XL
Basic_Programs_for_the_Atari_600XL_and_800XL directory listing
basic programsfor theatari 600xl800xldirectory
https://archive.org/details/Basic_Programs_for_the_Atari_600XL_and_800XL/Basic_Programs_for_the_Atari_600XL_and_800XL
BASIC programs for the Atari 600XL & 800XL : Knight, Timothy Orr : Free Download, Borrow, and...
Basic Programs for the Atari 600XL and 800XL
https://archive.org/details/Basic_Programs_for_the_Atari_600XL_and_800XL?view=theater&ui=embed&wrapper=false
BASIC programs for the Atari 600XL & 800XL : Knight, Timothy Orr : Free Download, Borrow, and...
Basic Programs for the Atari 600XL and 800XL
https://ultimon.com/
ULTIMON for Atari 1200XL, 600XL, 800XL, 800XLE, 65XE, 130XE, XEGS and Emulators
atari 1200xl