Hello everyone...
In need to upgrade my 600xl to 64k, I found three different places describing how I can do it:
https://atrey.karlin.mff.cuni.cz/~machek/atari/600xl64Ka.html
https://www.atarimax.com/freenet/freenet_material/12.AtariLibrary/2.MiscellaneousTextFiles/showarticle.php?108
http://mathyvannisselroy.nl/xl600k64.htm
It seems to me that the first one (with the R36 resistor) is the most popular but as far as I can understand they do the same job by finding different "r