Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!caen!wormwood.engin.umich.edu!milamber From: milamber@caen.engin.umich.edu (Daryl Scott Cantrell) Newsgroups: comp.sys.amiga.hardware Subject: Re: A3000/16 vs. A3000/25 non-CPU speed Summary: Confusion reigns.. Keywords: a3000 custom clock speed Message-ID: <1991Mar6.153125.22678@engin.umich.edu> Date: 6 Mar 91 15:31:25 GMT References: <4101.27d2e586@miavx1.acs.muohio.edu> <1991Mar6.142824.12241@hollie.rdg.dec.com> Sender: news@engin.umich.edu (CAEN Netnews) Organization: University of Michigan Engineering, Ann Arbor (ick) Lines: 46 In article <1991Mar6.142824.12241@hollie.rdg.dec.com> decwrl!mansw1.enet!krauss writes: >> >>In article <4101.27d2e586@miavx1.acs.muohio.edu> jwwalden@miavx1.acs.muohio.edu (Darc Tangent) writes: >> >>>I know that the new >>>custom chips in the A3000 are clocked at the same rate as the main processor >> >>This is the first time I read about custom chips running at a higher rate >>than 14.32 MHz (and even slightly slower in PAL Amigas) >>Processor Clock Rate on the chip bus ? You are not talking about a >>chip bus running at 25 MHz bus speed, are you ? >> [...] > >I don't no at which rate the custom chips are running, but as far as I remember >there is a jumper on the motherboard of the A3000 that changes some timings of >the customchips.(It has two settings: one for 16M and one for 25M.) > As far as I know, the custom chips in all Amigas run at 7.14 MHz (for now, hopefully). The 16/25 MHz clock in an A3000 drives a totally different bus. I think you might be thinking of the two pairs of shorting posts in the 3000 that configure ROMs based on the type of chip and the speed of the bus. I think these are for determining wait states and such.. As to the original question, the only differences between a 3000/25 and a 3000/16 are: oscillator 68030 rating FPU type/rating In other words, the entire 030 bus of a 3000/16 is built to go 25 MHz, but doesn't (unless you were to plop something into the 200-pin CPU slot).. So when you get that 040 accelorator, it will go 25 MHz in either. >>Holger Lubitz | holgerl@amiux.uucp >Michael Krauss #include >"krauss@mansw1.enet.dec.com" or "...!decwrl!mansw1.enet!krauss" -- +---------------------------------------+----------------------------+ | // Daryl S. Cantrell | These opinions are | | |\\\ milamber@caen.engin.umich.edu | shared by all of // | | |// Evolution's over. We won. | Humanity. \X/ | +---------------------------------------+----------------------------+