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- Path: sparky!uunet!stanford.edu!agate!soda.berkeley.edu!wjolitz
- From: wjolitz@soda.berkeley.edu (William F. Jolitz)
- Newsgroups: comp.unix.bsd
- Subject: Re: More on NMI problems.
- Date: 4 Sep 1992 18:26:47 GMT
- Organization: U.C. Berkeley, CS Undergraduate Association
- Lines: 34
- Message-ID: <1889p7INN5sn@agate.berkeley.edu>
- References: <1992Sep2.123248.17492@ponds.uucp>
- NNTP-Posting-Host: soda.berkeley.edu
-
- In article <1992Sep2.123248.17492@ponds.uucp> rivers@ponds.uucp (Thomas David Rivers) writes:
- >Well, I got much advice on my NMI problems; indicating that I probably
- >did, in fact, have a bad memory chip on my machine.
- >So; I grabbed testext.exe from SIMTEL20 and let it have at the machine,
- >to determine which chip was bad, etc....
-
- I missed your earlier inquiry, but I thought I should post a notice
- regarding "trap 19" problems.
-
- In particular, a student in Linkoping University sent me a fax regarding
- a problem with booting: he would get a "trap type 19 code..." message
- and the system would panic.
-
- Trap type 19 indicates an nmi trap (see trap.h). In this particular
- case, the problem was localized to the motherboard (a 486DX 33MHz ISA,
- made in Taiwan).
-
- There are two possibilities in this situation:
-
- 1. Bad memory parity. This could be a bad memory chip (run memory tests
- to confirm). However, it should be noted that some cheap boards have
- BIOS's which do not initialize memory correctly. In this case, one must
- clear memory blindly BEFORE touching it. If it is an inadaquate board,
- one might want to get a better (in-spec) one and use the other one for
- MS-DOS.
-
- 2. There is a difference between "expanded" (e.g. LIM) memory and
- "extended" (e.g. above 0x100000) memory. If any memory is allocated
- to "expanded" memory, then problems will occur.
-
- A number of people are experiencing 1) and 2) and have written me
- accordingly. I hope this helps isolate a few of those "mystery" problems.
-
- Lynne Jolitz.
-