pscmd="(jcabc2ps /Users/jc/w/tmp/Tune-4932-JohnWalsh.abc -F fmt/pdf_70.fmt +s 0.70 +maxs 2000 )>/Users/jc/w/tmp/Tune-4932-JohnWalsh.ps 2>>/Users/jc/w/tmp/Tune-4932-get.log" returned status 256.
http://john-chambers.us/~jc/music/book/JohnWalsh.abc

Error exit status 256; here are some files to check:
[P=tuneget V=1/1 B=0 scale=0.70 512x512 ]
filesizedescription
Tune-4932-JohnWalsh.abc 1114771 ABC music file with the extracted tune(s)
Tune-4932-JohnWalsh.ps 33898 PostScript
Tune-4932-JohnWalsh.txt 1114771 Plain-text file with the extracted tune(s)
Tune-4932-get.log 458031 Log file, useful mostly for debugging
Tune-49328-endo.abc 100 ABC music file with the extracted tune(s)
Tune-49328-endo.pdf 2217 Portable Data Format
Tune-49328-endo.ps 6 PostScript
Tune-49328-endo.txt 100 Plain-text file with the extracted tune(s)
Tune-49328-get.log 4550 Log file, useful mostly for debugging
These files should be available for 24 hours.