Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!rutgers!mit-eddie!husc6!seismo!rochester!kodak!elmgate!jdg From: jdg@elmgate.UUCP (Jeff Gortatowsky) Newsgroups: comp.sys.amiga Subject: 68881 in a 68010 Amiga (question) Message-ID: <535@elmgate.UUCP> Date: Fri, 14-Nov-86 08:08:52 EST Article-I.D.: elmgate.535 Posted: Fri Nov 14 08:08:52 1986 Date-Received: Sat, 15-Nov-86 02:57:38 EST Organization: Eastman Kodak Co., Rochester, NY Lines: 26 Keywords: Floating Point FPU 68881 68000 68010 Hardware I've asked this before and never really got the response I was looking for (I only received one or two) so I thought I'd rephrase it and try again. Since a 68010 must emulate the coprocessor interface that a 68020 has in microcode, it must read/write to addresses in memory that the 881's registers are wired to (CIR,etc). I would like to wire up such an interface as it's cheaper than any 020 modifications and should still be an improvement over software FP. I'm trying to use the Motorola guidelines for wiring an 881 to a 010. All I need to know is what address should the base register of the 881 be located at? Is there an official space in the Amiga memory map for an 881 in such a configuration? If not, where is a 'safe' place to put it? I don't want to conflict with other third party hardware I may add later if I can avoid it. Please, no responses about how the 020 uses 'cpu space' etc. I am familiar with the 020 and it's co-CPU interface. I just can't see spending 600 dollars for the CSA piggy back board (They told me it was going away anyways). Thanks in advance for any information/help/tips you can provide. -- Jeff Gortatowsky {allegra,seismo}!rochester!kodak!elmgate!jdg Eastman Kodak Company