Real-time clock
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From: HankG on 29 Dec 2005 07:28 I have an old '386 computer that my grandchildren use to run DOS based games which will not run on my newer computers. Well, it finally stopped running; would freeze after post. Examination found that bios information would not be retained. The board does not contain a battery. There is a Dallas Real Time Clock (1287/1187) chip which combines CMOS, battery, and clock functions. These seem to be available and are relatively inexpensive. I would attempt to replace it (socketed rather than directly soldered). Information on the chip indicates that they are inactive when received and must be activated for Intel or Motorola use. I assume that this refers to the CPU. My question: what is involved in 'activating' this chip and what (hardware/software) is required? Thanks. HankG
From: Ken on 29 Dec 2005 07:52 HankG wrote: > I have an old '386 computer that my grandchildren use to run DOS based games > which will not run on my newer computers. > > Well, it finally stopped running; would freeze after post. Examination > found that bios information would not be retained. The board does not > contain a battery. There is a Dallas Real Time Clock (1287/1187) chip which > combines CMOS, battery, and clock functions. > > These seem to be available and are relatively inexpensive. I would attempt > to replace it (socketed rather than directly soldered). > > Information on the chip indicates that they are inactive when received and > must be activated for Intel or Motorola use. I assume that this refers to > the CPU. > > My question: what is involved in 'activating' this chip and what > (hardware/software) is required? Thanks. > > HankG > > > By "Inactive," I think they mean they are disabled while removed from the circuit. If there is a jumper to be made in order for it to work, it is made when it is inserted into your socket. Once that is done, the battery function of the RTC is connected and ready for its function. At least all the RTC's I installed required no other action other than setting them in CMOS setup after being replaced.
From: HankG on 29 Dec 2005 08:16 "Ken" <user(a)domain.invalid> wrote in message news:A_Qsf.373956$zb5.184549(a)bgtnsc04-news.ops.worldnet.att.net... > HankG wrote: > > I have an old '386 computer that my grandchildren use to run DOS based games > > which will not run on my newer computers. > > > > Well, it finally stopped running; would freeze after post. Examination > > found that bios information would not be retained. The board does not > > contain a battery. There is a Dallas Real Time Clock (1287/1187) chip which > > combines CMOS, battery, and clock functions. > > > > These seem to be available and are relatively inexpensive. I would attempt > > to replace it (socketed rather than directly soldered). > > > > Information on the chip indicates that they are inactive when received and > > must be activated for Intel or Motorola use. I assume that this refers to > > the CPU. > > > > My question: what is involved in 'activating' this chip and what > > (hardware/software) is required? Thanks. > > > By "Inactive," I think they mean they are disabled while removed from > the circuit. If there is a jumper to be made in order for it to work, > it is made when it is inserted into your socket. Once that is done, the > battery function of the RTC is connected and ready for its function. At > least all the RTC's I installed required no other action other than > setting them in CMOS setup after being replaced. It makes sense. The claim of 'inactivity' referenced the battery, to save life. What about the reference to "Intel or Motorola"? HankG
From: C R Briggs on 29 Dec 2005 17:38 "HankG" <hank(a)invalid.com> wrote in message news:7I6dnXm56PT-Sy7eRVn-rg(a)comcast.com... >I have an old '386 computer that my grandchildren use to run DOS based >games > which will not run on my newer computers. > > Well, it finally stopped running; would freeze after post. Examination > found that bios information would not be retained. The board does not > contain a battery. There is a Dallas Real Time Clock (1287/1187) chip > which > combines CMOS, battery, and clock functions. > > These seem to be available and are relatively inexpensive. I would > attempt > to replace it (socketed rather than directly soldered). > > Information on the chip indicates that they are inactive when received and > must be activated for Intel or Motorola use. I assume that this refers to > the CPU. > > My question: what is involved in 'activating' this chip and what > (hardware/software) is required? Thanks. > Hank, You may need to do a bit of research before attempting this repair. There seems to be more than one type of "Dallas Real Time Clock chip", and some are not interchangeable. I had experience with a board which had a "Houston Tech HT12888A" which uses a VIA VT82885N chip. The VT82885N was meant to be a functional replacement for the DS12885 but did not meet the correct specifications. One or more system board manufacturers changed their design to match the specifications of this device. Therefore, you cannot replace it with a DS12885 chip or DS12887. For many users this will mean REPLACING the system board because the HT12888A is not commercially available. It may be possible to replace the battery on your existing chip - in my own case I was able to prise off the "plastic block" over the, which revealed the battery soldered to two of the chip "legs" which had been bent over the top of the chip. Good luck, -- C R Briggs btyguard-nospam(a)yahoo.co.uk
From: Ken on 29 Dec 2005 18:11
HankG wrote: > "Ken" <user(a)domain.invalid> wrote in message > news:A_Qsf.373956$zb5.184549(a)bgtnsc04-news.ops.worldnet.att.net... > >>HankG wrote: >> >>>I have an old '386 computer that my grandchildren use to run DOS based > > games > >>>which will not run on my newer computers. >>> >>>Well, it finally stopped running; would freeze after post. Examination >>>found that bios information would not be retained. The board does not >>>contain a battery. There is a Dallas Real Time Clock (1287/1187) chip > > which > >>>combines CMOS, battery, and clock functions. >>> >>>These seem to be available and are relatively inexpensive. I would > > attempt > >>>to replace it (socketed rather than directly soldered). >>> >>>Information on the chip indicates that they are inactive when received > > and > >>>must be activated for Intel or Motorola use. I assume that this refers > > to > >>>the CPU. >>> >>>My question: what is involved in 'activating' this chip and what >>>(hardware/software) is required? Thanks. >>> > > >>By "Inactive," I think they mean they are disabled while removed from >>the circuit. If there is a jumper to be made in order for it to work, >>it is made when it is inserted into your socket. Once that is done, the >>battery function of the RTC is connected and ready for its function. At >>least all the RTC's I installed required no other action other than >>setting them in CMOS setup after being replaced. > > > It makes sense. The claim of 'inactivity' referenced the battery, to save > life. What about the reference to "Intel or Motorola"? > > HankG > > I cannot imagine why there would be any reference to either of them? My guess is it is just a generic comment to alert the user that CMOS must be set after the installation. Ken |