16 Jun
2011
16 Jun
'11
9:07 p.m.
No. I worked with both SCO and ISC linux in the late 80's and early 90's and run level 5 was used for X. In fact I think it was used also in DGUX for X.
I don't know about ISC UNIX (aka Interactive UNIX) but SCO did not use run level 5 for X. I cut my teeth on System V UNIX including SCO UNIX 3.2 and seeing X in runlevel 5 these days still feels wrong to me all these years later, though I have to come realize how convenient it is.