So my original post was going include be "What does BOSS-XL do other than 800 compatibility" but looks like this page answered all my questions! http://www.cyberroach.com/analog/an25/xlboss.htm Referenced also in Mapping the Atari, Appendix Twelve on atariarchives.org: https://www.atariarchives.org/mapping/appendix12.php "A hardware solution is available: the XL BOSS chip from Allen MacroWare." Anyhow, I used to have this OS in my 130XE that my dad had modded for me back in the day as one of 4
Wow... good things come to those that ask. Thank you to an anonymous sender for their PM!
XLBOSS1.bin seems to be most likely the OS I remember, I a hex editor I can see the MEMOPAD replacement header "THE XL BOSS V1.0" and "LOAD ERROR" instead of "BOOT ERROR" , and 4KB of blank space at the beginning of the ROM
XLBOSS2.bin has a lot more data in the first 4KB, the original "BOOT ERROR" again, and I see the string "macromon xl © allen macroware" in hex editor, so the disk based macromon