Xref: utzoo misc.forsale:1732 comp.sys.ibm.pc:16996 Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!uwmcsd1!bbn!rochester!rutgers!columbia!cunixc!suh From: suh@cunixc.columbia.edu (Kenneth Suh) Newsgroups: misc.forsale,comp.sys.ibm.pc Subject: Re: Intel Coprocessors for sale Keywords: 8087 80287 IBM Message-ID: <786@cunixc.columbia.edu> Date: 8 Jul 88 17:13:57 GMT References: <143@celerity.UUCP> <1400@lznv.ATT.COM> Reply-To: suh@cunixc.cc.columbia.edu (Kenneth Suh) Distribution: na Organization: Columbia University Lines: 27 In article <1400@lznv.ATT.COM> psc@lznv.ATT.COM (Paul S. R. Chisholm) writes: >< "Would you buy a used operating system from these guys?" > >Um, no. For a system with an 8 MHz 8088 or 8086 (e.g., AT&T PC 6300, >original Compaq Deskpro, IBM PS/2 Models 25 and 30), you want an 8 MHz >8087-2. The 5 MHz 8087-3 is suitable for 4.77 MHz machines (PC and XT >compatibles). That's a good price for an 8087-3, but if it doesn't >work reliably in your (8 MHz) system, it's no bargain at any price. > >No, I *don't* know what speed a 8087-1 runs at. > >-Paul S. R. Chisholm, {ihnp4,cbosgd,allegra,rutgers}!mtune!lznv!psc The 8087-1 was a brain-damaged Intel Math Coprocessor which was 5 MHz. Also, doesn't the math co-processor run at one-third the boards crystal speed. I know that the cpu runs at half the crystal speed on an AT. /ken Kenneth Suh PATH: suh@CUNIXC.CC.COLUMBIA.EDU Kermit Distribution SY.SUH@CU20B.BITNET Columbia University Center for ..!rutgers!columbia!cunixc!suh Computing Activities 612 West 115th Street New York, NY 10025