iverson@cory.BERKELEY.EDU (Tim Iverson) (01/25/86)
After reading the articles on improving the speed of the AT with faster chips and faster xtals, I am wondering if this is possible for the PC and the XT. I have replaced the 5Mhz 8088 with an 8Mhz V20, which works fine. But, when I replaced the clock chip with the one for the V20, I got a blank screen on cold-boot - not even a cursor. The V20 type clock chip divides the xtal frequency by 1/2 instead of 1/3 and has a 50% duty instead of 33%. All of this is fine for the V20, so something else must be going wrong. If I had a 'scope, I could tell you more, but I don't. Any clues to resolving this problem would be appreciated. Thanks, Tim Iverson. (iverson@cory.berkeley.edu)
tankus@hsi.UUCP (01/27/86)
> > After reading the articles on improving the speed of the AT with > faster chips and faster xtals, I am wondering if this is possible for the > PC and the XT. stuff removed from here for brevity ... > Any clues to resolving this problem would be appreciated. > > Thanks, > Tim Iverson. > (iverson@cory.berkeley.edu) The most recent PC Week (1/21/86) had some info out on companies who are producing 80286 motherboards that completely replace the XT motherboard so that voila!, you have a 100% compatilble (their claim) AT clone. It may bear looking into. -- Interested parties please contact: Ed Tankus Health Systems Int'l 100 Broadway New Haven, CT 06511 (203) 562-2101 or {noao!ihnp4!yale!}!hsi!tankus
glen@intelca.UUCP (01/30/86)
> I have replaced the 5Mhz 8088 with an 8Mhz V20, which works fine. > But, when I replaced the clock chip with the one for the V20, I got a blank > screen on cold-boot - not even a cursor. The V20 type clock chip divides the > xtal frequency by 1/2 instead of 1/3 and has a 50% duty instead of 33%. All > of this is fine for the V20, so something else must be going wrong. If I had > a 'scope, I could tell you more, but I don't. > > Any clues to resolving this problem would be appreciated. > > Thanks, > Tim Iverson. > (iverson@cory.berkeley.edu) For a computer to run faster, not only must the CPU be able to run at a higher clock rate, but so must the memory and I/O subsystems. It just so happens that the memory and I/O of an AT can run at 8MHz (or in some cases more). I suspect the XT memory and/or I/O does not. Also, if you have a Color/Graphics Adapter (as opposed to a IBM mono, or Hercules, etc.) then the CPU XTAL also affects the display rate and your monitor may not sync up. (Even if it can, the CPU must run some initialization code before you see the cursor). -- ^ ^ Glen Shires, Intel, Santa Clara, Ca. O O Usenet: {ucbvax!amd,pur-ee,hplabs}!intelca!glen > ARPA: "amd!intelca!glen"@BERKELEY \-/ --- stay mellow