Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/JamesOswald/CPC/13201_John_Hays_bonny_Lassie.abc/all"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-90198-all.ps) >>/Users/jc/w/tmp/Tune-90198-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/JamesOswald/CPC/13201_John_Hays_bonny_Lassie.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
Tune-90198-Buningford_Assembly.abc 759 ABC music file with the extracted tune(s)
Tune-90198-Buningford_Assembly.gif 0 Graphics Interchange Format, the proprietary scan-line picture format
Tune-90198-Buningford_Assembly.ps 35779 PostScript
Tune-90198-Buningford_Assembly.txt 759 Plain-text file with the extracted tune(s)
Tune-90198-all.abc 180 ABC music file with the extracted tune(s)
Tune-90198-all.ps 6 PostScript
Tune-90198-all.txt 180 Plain-text file with the extracted tune(s)
Tune-90198-get.log 9541 Log file, useful mostly for debugging
These files should be available for 24 hours.