pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-26359-Unknown_18.ps) >>/Users/jc/w/tmp/Tune-26359-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/abc/mirror/kirby98.fsnet.co.uk/un/Unknown_18.abc

Error exit status 256; here are some files to check:
[P=get.cgi V=1/1 B=0 scale=0.60 512x512 PNG]
filesizedescription
Tune-26359-Unknown_18.abc 329 ABC music file with the extracted tune(s)
Tune-26359-Unknown_18.ps 34036 PostScript
Tune-26359-Unknown_18.txt 329 Plain-text file with the extracted tune(s)
Tune-26359-get.log 4813 Log file, useful mostly for debugging
These files should be available for 24 hours.