pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-6811-abc_files.ps) >>/Users/jc/w/tmp/Tune-6811-get.log 2>&1" returned status 256
http://www.folksong.org.nz/abc_files.html

Error exit status 256; here are some files to check:
[P=get.cgi V=1/1 B=0 scale=0.60 512x512 PNG]
filesizedescription
Form_68112.log 0 Log file, useful mostly for debugging
Tune-6811-abc_files.abc 659 ABC music file with the extracted tune(s)
Tune-6811-abc_files.ps 34985 PostScript
Tune-6811-abc_files.txt 659 Plain-text file with the extracted tune(s)
Tune-6811-get.log 4266 Log file, useful mostly for debugging
Tune-68110-get.log 31192 Log file, useful mostly for debugging
Tune-68112-get.log 3034 Log file, useful mostly for debugging
Tune-68115-get.log 0 Log file, useful mostly for debugging
These files should be available for 24 hours.