pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-6937-4101-the_Island_of_Mull.ps) >>/Users/jc/w/tmp/Tune-6937-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/Gow/CR/4101-the_Island_of_Mull.abc1.abc

Error exit status 256; here are some files to check:
[get.cgi V=1/1 B=0 scale=0.55 512x512 PNG]
filesizedescription
Coll_69375.log 2437311 Log file, useful mostly for debugging
Form_69374.log 854 Log file, useful mostly for debugging
Tune-6937-4101-the_Island_of_Mull.abc 1108 ABC music file with the extracted tune(s)
Tune-6937-4101-the_Island_of_Mull.ps 39892 PostScript
Tune-6937-4101-the_Island_of_Mull.txt 1108 Plain-text file with the extracted tune(s)
Tune-6937-get.log 4730 Log file, useful mostly for debugging
These files should be available for 24 hours.