Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!cis.ohio-state.edu!ucbvax!pdi.UUCP!shoshana From: shoshana@pdi.UUCP (Shoshana Abrass) Newsgroups: comp.sys.sgi Subject: 4 Mb SIMMS Message-ID: <9106252336.AA00574@koko.pdi.com> Date: 25 Jun 91 23:36:50 GMT Sender: daemon@ucbvax.BERKELEY.EDU Distribution: world Organization: The Internet Lines: 50 We've started having a weird problem with our 4 Mb SIMMS. Background: We're using 100% Toshiba chips. Some of our simms were built by Kingston, some of them were built by Toshiba - but it doesn't make a difference as far as our problem goes. We've been using the 4 Mb SIMMS in our 4D 25's since at least september and currently have them in 18 machines. At first the simms worked fine. But then a few times I noticed that when I powered down a machine, I would get an error on startup. This error occurs during power-on diagnostics and flashes on the screen *very* briefly (but can be stopped with -S). After the error, the machine won't boot and an hinv at the PROM shows 0 memory. The entire message is shown below. The weird part: The problem doesn't mean that the hardware is bad. At first we panicked and called the hotline; they replaced the e-mod and things did work better. But then we realized that by just wiggling the simms, we could make the problem go away. I've now done this more than a dozen times on various machines . The problem always occurs at boot time - the machine runs without problems once it's up. Wiggling or, at worst, removing and re-installing the simms always fixes the problem. I guess that the physical fit between some 4 Mb simms and some iris memory slots is a bit loose or otherwise imperfect. I'm posting to the net because (1) others may have this problem some day (2) I'm wondering if anyone has had this problem and found a permanent fix? (3) I thought SGI gurus might have some insight into the error message. ------------- EXCEPTION: Exception pc: 0xbfc00e0c Cause register: 0x1c Status register: 0x88004 Error Addr register: 0x400000 Local I/O interrupt register: 0xbf Parity error register: 0xe4 Registers (in hex): [many registers listed] ------------ -shoshana shoshana@pdi.com pdi!shoshana@sgi.com --