Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!gem.mps.ohio-state.edu!ginosko!uunet!mitel!melair!low From: low@melair.UUCP (Rick Low) Newsgroups: comp.sys.m68k Subject: Re: Need help with 68881 Summary: The User's Manual has this info. Message-ID: <283@melair.UUCP> Date: 18 Aug 89 19:53:27 GMT References: <1135@kuling.UUCP> Organization: MEL Defence Systems Ltd., Ottawa, Canada Lines: 48 In article <1135@kuling.UUCP>, jonasf@kuling.UUCP (Jonas Flygare) writes: > I am writing some programs using the 68881, and have a small problem.. > I have tried to get documentation on the 68881, and so far the best one > is the technical summary BRE265R3. Try to get MC68881/MC68882 Floating-Point Coprocessor User's Manual, Englewood Cliffs, NJ, USA 07632, Prentice Hall Inc., 1987. ISBN 0-13-566936-7 I got mine from the local Motorola office. > On the front page it states that > the FPU have 22 constants available in the on-chip ROM. > "How nice I thought, _just_ what I need.." However, I cannot find any > reference to HOW I access those available constants.. ;-) > Anyone know how? Also, pointers to better documents describing the FPU > would be appreciated. email preferred. The FMOVECR instruction (Move Constant ROM) can load the following constants from 68881 ROM into a coprocessor register: pi log10(2) e log2(e) log10(e) 0.0 ln(2) ln(10) 10^n, n=0,1,2,4,8,16,32,64,128,256,512,1024,2048,4096 That makes 22 constants. > Thanks in advance.-- > Jonas Flygare (aka Flax) |If God had wanted me to have opinions he > email: jonasf@kuling.UUCP |would have given me UseNet access.. > real: Vaktargatan 32 F:621 | > S-754 22 Uppsala Sweden | Rick Low MEL Defence Systems Limited, Ottawa, Canada +1 613 836 6860 mitel!melair!low@uunet.UU.NET -- Rick Low MEL Defence Systems Limited, Ottawa, Canada +1 613 836 6860 mitel!melair!low@uunet.UU.NET