What is the origin of "newbie"?

Also seen as "noobie", "n00b", etc.

Etymonline gives an origin by 1969, possibly in the military. Is there a more definite origin anywhere? I know it is was also common on the Usenet, but of course any such use must have been post-1979 when Usenet was invented.

I know that the suffix "-bie" (as in freebie, etc.) is not uncommon, but I'm looking for specific usages of that suffix with the word "new".

Per comment, OED says "origin uncertain". Personally, my money's on it being a variant of...

newie - Chiefly U.S. and Austral. A person who is new to a place, situation, etc.; a newcomer; a novice.

1856 B. H. Hall Coll. College Words (rev. ed.) , Newy, at Princeton College, a fresh arrival.
1917 Truth (Sydney) 1 Apr. 6/7 Two newies had a rough-up at Rozelle.
1961 A. Berkman Singers' Gloss. Show Business Jargon 61 Newies (Var.), novices; neophytes.

Regardless of whether it was formed by b-insertion there (as with free = freebie), OED seems quite happy to say newbie is slang (orig. U.S. Mil.)., attested from the early 70s.

Its etymology is uncertain. It may derive from "newie", which is attested in U.S. and Australian sources of the 1850s and means a neophyte in a place or situation; alternatively, it may derive from the British public school slang "new boy" or "new blood", which is attributed to the same era and was applied to a schoolboy in his first term.

There was an episode of Highway Patrol that aired 4/14/58 where a delivery driver describes a waitress to Dan Matthews as a “newbie”. So it’s at least that old.

I can confirm the terms specific military usage going back at least to 1942, when the SeaBees were formed. In the US Navy if you are a member of the Construction Battalions you are referred to as a ‘SeaBee’. When someone is first transferred into the unit (enlisted or officer) they are referred to as being ‘NewBees’. Even experienced personnel who are transferred in from the fleet (sea going Navy) are referred to as NewBees. “The new Chief master at arms is a NewBee and needs to learn how things are done in the battalions.”