I don't know if this is common knowledge, but there is a set of
"Downloadable MPE/iX Documentation" links on http://docs.hp.com/mpeix/.
<http://docs.hp.com/mpeix/> Among others, this has the MPE/iX Shell and
Utilities Reference Manuals, Vol 1 and and Vol 2, and the ODBCLINK/SE
Reference Manual. Nice to have these as softcopies.