Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!yale!umich!samsung!uakari.primate.wisc.edu!caen!mondo.engin.umich.edu!billkatt From: billkatt@mondo.engin.umich.edu (billkatt) Newsgroups: comp.sys.mac.programmer Subject: Re: F Emulator, Just what the hey is it Message-ID: <1990Aug10.184535.11051@caen.engin.umich.edu> Date: 10 Aug 90 18:45:35 GMT References: <1990Aug8.100755.1@mel.cipl.uiowa.edu> <19493@well.sf.ca.us> <82893@tut.cis.ohio-state.edu> Sender: news@caen.engin.umich.edu (CAEN Netnews) Reply-To: billkatt@mondo.engin.umich.edu (billkatt) Organization: Computer Aided Engineering Network (CAEN), University of Michigan Lines: 32 In article <82893@tut.cis.ohio-state.edu> brian e topping writes: >In article <19493@well.sf.ca.us> oster@well.sf.ca.us (David Phillip Oster) writes: >>68000 instructions that begin with the hex code 0xFxxx are reserved for >>coporcessor chips. If you don't have a coprocessor, then you get a software >>interrupt to an interrupt routine that is supposed to emulate the coprocessor. Says who? I don't recall reading and documentation on the 680x0's which says you must or even should emulate a math coprocessor if you don't have one. Clearly, it is a good idea, especially since more than one program will bomb on Apple's new Macs with 68030's (020's?) and no math coprocessor, simply because some programs assume 68030's and 68881/2's always go together. But Apple didn't do anything WRONG by not emulating one. > >Why then was SANE implemented as it was? It seems that it would be better >to have SANE respond to the interrrupts, then there would be no need for >different versions of programs like Wings depending on whether or not you have >an 881. SANE is more accurate than the 881/882. SANE uses 80-bit numbers instead of 96-bit numbers. SANE has routines for converting to/from ASCII strings, the 881 only does number crunching, how you get the numbers in and out are your problem. SANE just wasn't meant as a replacement for the 881, it was meant as a totally different method of approaching math processing. ============================================================================= Steve Bollinger ____/| 909 Church St. Apt C \ o.O| Ann Arbor, Mi. 48104 =(_)= (313)-662-4073 -home (313)-763-3070 -work U billkatt@mondo.engin.umich.edu -ACK ACK ACK ACK! "thhhhppppttt!"