pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-53133-0943_GEN_KNOXS_MARCH.ps) >>/Users/jc/w/tmp/Tune-53133-get.log 2>&1" returned status 256
http://roaringjelly.org/~jc/music/book/BostonCollection/0943_GEN_KNOXS_MARCH.abc

Error exit status 256; here are some files to check:
[P=tuneget V=1/1 B=0 scale=0.70 512x512 PNG]
filesizedescription
Tune-53133-0943_GEN_KNOXS_MARCH.abc 746 ABC music file with the extracted tune(s)
Tune-53133-0943_GEN_KNOXS_MARCH.ps 37097 PostScript
Tune-53133-0943_GEN_KNOXS_MARCH.txt 746 Plain-text file with the extracted tune(s)
Tune-53133-get.log 4812 Log file, useful mostly for debugging
These files should be available for 24 hours.