To delve into the depths of history, one must turn to the ancient archives: Usenet, that is.
The oldest use of "horkage" is 1991/04/12 by Shaun Case in comp.os.msdos.programmer:
If you are interested in this program, check your
local list of newsgroups for c.b.i.p. and engage in major
horkage.
Notice that there is no sense of "broken" here; "horkage" is being used in the ordinary sense of "hork": "to vomit" (onomatopoeia).
The oldest use in the other sense (which I was not familiar with before doing this research) is 1997/04/11 by Jose Nazario on misc.forsale.computers.workstation, but more interesting is the response by Thomas Gunnar Sparks:
: >>try and isolate horkage before your morning coffee.
: I have to ask... just what, exactly, is "horkage"?
I remember hearing the term when I started BBSing many moons ago... I
first heard them uttered from some Berkleyites, specifically tjames :)
There was a Timothy James doing an undergrad at Berkeley at the right time, but I wasn't able to track anything further.
Also of note is this question regarding the related "horked" by Walter Howard in alt.folklore.computers on 1994/02/10:
hork - 1. transitive, destroy. "When he booted the new version
it horked the entire database".
2. intransitive, die, crash. "OS/2
went to access the partition table and then it just horked".
The replies mention that "hork" can also be used for "to steal", particularly in Canadian.