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- Xref: sparky comp.org.eff.talk:5763 comp.os.mach:1224 comp.unix.bsd:5442 gnu.misc.discuss:2978 misc.int-property:945 alt.suit.att-bsdi:278
- Path: sparky!uunet!wupost!usc!elroy.jpl.nasa.gov!suned1!nosc!crash!fpm
- From: fpm@crash.cts.com (Frank Maclachlan)
- Newsgroups: comp.org.eff.talk,comp.os.mach,comp.unix.bsd,gnu.misc.discuss,misc.int-property,alt.suit.att-bsdi
- Subject: 386BSD lockups caused by ULSI 387 coprocessor
- Summary: ULSI 387 coprocessor can lock up!
- Keywords: 387,ULSI,lockup
- Message-ID: <1992Sep09.202141.9124@crash>
- Date: 10 Sep 92 03:21:41 GMT
- References: <1992Sep8.135040.5243@pegasus.com> <BRUNER.92Sep8172455@sp15.csrd.uiuc.edu> <1992Sep10.015507.27974@fcom.cc.utah.edu>
- Followup-To: comp.unix.bsd
- Distribution: na
- Organization: CTS Network Services (crash, ctsnet), El Cajon, CA
- Lines: 22
-
- Ever since I upgraded the motherboard in my 386BSD 0.1 system from
- a 386/20, 64 kb cache, w/ 4 mb of memory, no 387 to an OPTi chipset
- based 386/40 w/ 64 kb cache, ULSI 387 coprocessor, and 16 mb of ram,
- I experienced occasional lockups. The system would simply freeze
- and I had to hit the reset button to recover. These lockups were
- traced to my ULSI 387 math coprocessor. I wrote a simple test program
- which computed sin(5.0) in an infinite loop; this would lock up an
- otherwise idle system after 4,000 to 150,000 iterations. I then
- modified npxprobe() in /sys/i386/isa/npx.c to not find the 387 and
- the problem went away.
-
- I called ULSI and was told that they were aware of the problem (they
- had seen it on an SCO Unix system). It seems that the ULSI part gets
- into a state where its BUSY output to the 386 is permanently asserted
- and the system locks up. The person I talked to suggested that I ex-
- change the ULSI 387 for a Cyrix equivalent. I called my vendor and
- got an RMA to return the ULSI part in exchange for a Cyrix 387.
-
- --
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