Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/JamesOswald/CPC/13022_the_Mill_Mill_O.abc/all"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-6404-all.ps) >>/Users/jc/w/tmp/Tune-6404-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/JamesOswald/CPC/13022_the_Mill_Mill_O.abc/all

Error exit status 256; here are some files to check:
[get.cgi V=1/1 B=0 scale=0.55 512x512 PNG]
filesizedescription
Coll_64043.log 271687 Log file, useful mostly for debugging
Tune-6404-all.abc 173 ABC music file with the extracted tune(s)
Tune-6404-all.ps 6 PostScript
Tune-6404-all.txt 173 Plain-text file with the extracted tune(s)
Tune-6404-get.log 4069 Log file, useful mostly for debugging
Tune-64044-get.log 1549 Log file, useful mostly for debugging
Tune-64046-CR77.abc 2006 ABC music file with the extracted tune(s)
Tune-64046-CR77.ps 47798 PostScript
Tune-64046-CR77.txt 2006 Plain-text file with the extracted tune(s)
Tune-64046-get.log 4420 Log file, useful mostly for debugging
These files should be available for 24 hours.