pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-20865-dim.ps) >>/Users/jc/w/tmp/Tune-20865-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/EliasHowe/MusiciansCompanionP3/dim.abc

Error exit status 256; here are some files to check:
[P=tuneget V=1/1 B=0 scale=0.70 512x512 PNG]
filesizedescription
Form_20865.log 872 Log file, useful mostly for debugging
Tune-20865-dim.abc 221 ABC music file with the extracted tune(s)
Tune-20865-dim.ps 6 PostScript
Tune-20865-dim.txt 221 Plain-text file with the extracted tune(s)
Tune-20865-get.log 3930 Log file, useful mostly for debugging
These files should be available for 24 hours.