If not it should be very close. It's pre-1995 (priority date 1985, Filing 1988, Publication 1990) [1], so it'd be the longer of 20 years from filing date or 17 from date of issue as the basic time. However, there are compensatory adjustments for certain delays in issuance that could apply, Intel could possibly have submarined it to some extent (pre-WTO Uruguay Round), and #5,321,836 looks related [2]. I vaguely remember there have been issues with uneven expiration around the world for some older stuff too. So I have no idea exactly all that would add up, it'd be neat if the FSF or EFF or someone had done some calculations on it. Still, it's definitely an interesting question, we should relatively soon be approaching the point where, even taking into account 1990s IP extension shenanigans, all patents to tech from that era will expire, and expiration will become a lot more regular once the WTO-normalized ones are all that's left. There was a pretty rapid curve of basic developments in the 90s and early 00s, and as all that becomes available over the next decade there might be some interesting new possibilities in development.
1. http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=H...
2. http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=H...