Ask Slashdot:Booting XTerminals

Ken Crandall writes in with today's Ask Slashdot question. He asks "Does anyeone know how to boot NCD Xterminals (specifically NCD19R's, NCD15R's, and NCD HMX's from Linux? Currently we boot them from OpenVMS (which, if anyone is familiar with VMS, knows why I'm asking) but I'd like to boot them from Linux."