Got HTTP status 404 Not Found for "http://roaringjelly.org/~jc/music/book/1784/blank.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-5070-blank.ps) >>/Users/jc/w/tmp/Tune-5070-get.log 2>&1" returned status 256
http://roaringjelly.org/~jc/music/book/1784/blank.abc

Error exit status 256; here are some files to check:
[P=tuneget V=1/1 B=0 scale=0.70 512x512 PNG]
filesizedescription
Coll_50709.log 148014 Log file, useful mostly for debugging
Form_50708.log 1118 Log file, useful mostly for debugging
Tune-5070-RobertBremner_CSRCD2.abc 163 ABC music file with the extracted tune(s)
Tune-5070-RobertBremner_CSRCD2.ps 6 PostScript
Tune-5070-RobertBremner_CSRCD2.txt 163 Plain-text file with the extracted tune(s)
Tune-5070-blank.abc 142 ABC music file with the extracted tune(s)
Tune-5070-blank.ps 6 PostScript
Tune-5070-blank.txt 142 Plain-text file with the extracted tune(s)
Tune-5070-get.log 8185 Log file, useful mostly for debugging
Tune-50700-get.log 55638 Log file, useful mostly for debugging
Tune-50705-CR3-abc2.abc 94746 ABC music file with the extracted tune(s)
Tune-50705-CR3-abc2.txt 94746 Plain-text file with the extracted tune(s)
Tune-50705-get.log 63009 Log file, useful mostly for debugging
Tune-50709-get.log 5618 Log file, useful mostly for debugging
These files should be available for 24 hours.