thj@mtcchi.uucp (XT0221000-Tom Hjellming(ZG90210)0000) (07/16/90)
klh@mtune.ATT.COM (Ken Hinds) writes: >From article <1990Jul11.172043.525@bigsur.uucp>, by mussar@bcars53.uucp (G. Mussar): >> In article <169@evtprp0b.UUCP> tea6219@evtprp0b (Terry E. Acker) writes: >>>I have an XT with a V20 processor running at 8/4.77Mtz. What speed >>>coprocessor do I need. If there are different speed 8087s, can I >>>use a 4.77Mtz 8087 and set the system speed to 4.77? What if I run >>>the system at 8Mtz with a 4.77Mtz 8087? Will it work? Will it >>>overheat? >> >> If you plan on always running at 4.77 MHz, no problem. If you switch to 8 MHz, >> chances are the system won't even boot/run. This is based on trying the same >> experiment with a 4.77/10 MHz XT. YMVM. Even if if does boot/run, the 8087 >> (which normally runs pretty warm) will run VERY hot and this will decrease its >> life significantly. >Well, I have a dual speed 8088 micro processor in my Leading Edge >Model D and I have added an 8087 math coprocessore but, it is listed >as an 8087-2 which implies dual speed... Sorry I don't recall the >manufacturer but, I'm sure you could find it if you ask for it specifically. I'm not sure if this is what you meant, but the '-2' on the 8087 does _not_ mean dual speed. The 8087-2 is the 8MHz version of the 8087. To the original poster: I have an 8Mhz 8087 (the 8087-2) that I don't need anymore (I've since sold the PC and upgraded to a 386). Make me an offer... Tom Hjellming Software Consultant Analysts International Corp. (AiC) Schaumburg, IL ...!uunet!tellab5!mtcchi!thj { Usual dislaimers probably apply. } -- Tom Hjellming Software Consultant Analysts International Corp. (AiC) Schaumburg, IL