jmidili@hub.cs.jmu.edu (jeff midili) (04/04/91)
I was wondering if it is possible to replace a 16mhz 386sx with a 20mhz chip. Has anyone done this? Do the BIOS need to be replaced too? Are any companies offering a trade in value for the old chip for a new one??? Any help would be appreciated. jeff midili jmidili@hub.cs.jmu.edu
engle@wdl1.wdl.loral.com (David Engle) (04/05/91)
In article <1991Apr4.043028.9227@hub.cs.jmu.edu> jmidili@hub.cs.jmu.edu (jeff midili) writes: >I was wondering if it is possible to replace a 16mhz 386sx with >a 20mhz chip. Has anyone done this? Do the BIOS need to be >replaced too? Are any companies offering a trade in value for >the old chip for a new one??? > You may find that your 386SX mother board has a jumper selection option for the clock speed. The first 386SX-16 I owned had one of these, I just moved the jumper and the system ran just fine. The memory chips in the system were already of a fast enough speed to handle the new clock rate. I asked two friends in the PC business about this and both replied they had done similar things and found that most (but not all) systems would run just fine at the higher speed. Your mileage may vary, etc. -- David Engle, KE6ZE - engle@wdl1.wdl.loral.com - 408/473-4419 @ work Facts, what facts? I don't got to show you no stinking facts. These are opinions expressed here.
umcarls9@ccu.umanitoba.ca (Charles Carlson) (04/05/91)
In <1991Apr4.164920.5203@wdl1.wdl.loral.com> engle@wdl1.wdl.loral.com (David Engle) writes: >In article <1991Apr4.043028.9227@hub.cs.jmu.edu> jmidili@hub.cs.jmu.edu (jeff midili) writes: >>I was wondering if it is possible to replace a 16mhz 386sx with >>a 20mhz chip. Has anyone done this? Do the BIOS need to be >>replaced too? Are any companies offering a trade in value for >>the old chip for a new one??? Of course you could, if you had the eyesight of an owl and the agility of a cat. You're looking at desoldering/soldering ~100 pins less than a millimeter apart. I've never seen any socketed SX chips, just surface mount. No BIOS changes are necessary. Only IBM had the nerve to govern a BIOS. >You may find that your 386SX mother board has a jumper selection option >for the clock speed. The first 386SX-16 I owned had one of these, I just >moved the jumper and the system ran just fine. The memory chips in the >system were already of a fast enough speed to handle the new clock rate. Same with mine, but I also had to add a 40Mhz oscillator. All my chips are stamped 16Mhz, but I've been running the system at 20 for several weeks now, 24hrs a day, without a single problem. None of the C&T chips are even warm to the touch, and the SX chip itself is only slightly warm.
jerry@gumby.Altos.COM (Jerry Gardner) (04/06/91)
In article <1991Apr4.043028.9227@hub.cs.jmu.edu> jmidili@hub.cs.jmu.edu (jeff midili) writes: >I was wondering if it is possible to replace a 16mhz 386sx with >a 20mhz chip. Has anyone done this? Do the BIOS need to be >replaced too? Are any companies offering a trade in value for >the old chip for a new one??? Replacing just the 386sx with a faster part won't increase the speed of your machine. You also have to increase the clock input to the CPU, usually by replacing the crystal or clock oscillator. This proceedure may or may not be reliable depending how much margin was designed into the machine. -- Jerry Gardner, NJ6A Altos Computer Systems UUCP: {sun|pyramid|sco|amdahl|uunet}!altos!jerry 2641 Orchard Parkway Internet: jerry@altos.com San Jose, CA 95134 Help stamp out vi in our lifetime. (408) 432-6200
edm@hpfcmdd.hp.com (Ed Moore) (04/06/91)
The MHz rating of the processor chip is the maximum speed that Intel certifies it to operate reliably. So the 20 MHz chip should work just fine in your 16 MHz system. The system clock will still drive it at 16 MHz.