Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!zaphod.mps.ohio-state.edu!unix.cis.pitt.edu!dsinc!bagate!cbmvax!daveh From: daveh@cbmvax.commodore.com (Dave Haynie) Newsgroups: comp.sys.amiga.advocacy Subject: Re: The Amiga's Future Message-ID: <22308@cbmvax.commodore.com> Date: 10 Jun 91 19:39:45 GMT References: <16647@darkstar.ucsc.edu> <231@touch.touch.com> <#g1H3+$o@cs.psu.edu> <12901@uwm.edu> Reply-To: daveh@cbmvax.commodore.com (Dave Haynie) Organization: Commodore, West Chester, PA Lines: 77 In article <12901@uwm.edu> zark@csd4.csd.uwm.edu (Steven M Kosloske) writes: >In article <#g1H3+$o@cs.psu.edu> melling@cs.psu.edu (Michael D Mellinger) writes: >>In article <231@touch.touch.com> mikeh@touch.touch.com (Mike Haas) writes: >> The A3000 can handle 128Meg or RAM...without even blinking! In >> fact...it's expandable to to 1.8 GIG!!! (a GIG, for you mac folks who >> never deal with such numbers, is 1024 Meg). That's real memory, on the >> bus! >Wait a minute here. OK, the Amiga can have 1.8 GB of RAM, in theory. Is >there any product on the market which will let you do this? The A3000/A3000T will. They physically support up to 1.75GB of RAM (or other stuff) in their expansion bus. >No? Then it's impossible. IMPOSSIBLE, no matter what the CPU can do. An >80386 can access, what, 4 GB of RAM? As far as I know, the best you could do >today, if you packed every slot with RAM would probably be around 128 MB. You're confusing the issues here. Sure, the '030 and the '386 can each physically address 4GB of memory. Most systems built around these processors don't let you get anywhere close to that much memory. A '386 with only an ISA expansion bus typically limits you to 16MB of memory, total. That's a board design limit, not the '386's limit. Some '386 boards let you drop in some extra memory in a private memory slot, still not that close to 4GB; the board limit might be 16MB or 128MB. >So the 4 GB is also IMPOSSIBLE. The Mac can access 16MB on a 68000 machine, >or on the 68030 machines, 4GB of RAM. No. The 68000 can address 16MB of RAM, the 68030 can address 4GB of RAM. That says nothing about what a Mac can do. In theory, a Mac can support 256MB of RAM per NuBus slot, so a full sized Mac II with display card can support an additional 1.25MB of RAM, over and above what's on the motherboard (actually, in theory, around 1.33MB of RAM, though only 1.25MB is contiguous, due to the strange memory architecture of NuBus). NuBus RAM is, however, slow. >This limit is also IMPOSSIBLE, since there is no way to pack that much RAM >into a computer. Actually, using the latest 16Mbit chips, there's no challenge fitting 4GB of RAM into a machine with around 4 ISA sized expansion cards. If you got clever with high density SIMM modules and used the new real small surface mount package from Mitsubishi, you might even manage it with 4MB parts. >The physical truth is that a IBM-compat can hold 64MB max (I think this is the >limit today, correct me if I'm wrong) You're wrong. There's no standard for motherboard RAM amoung IBM compatibles. You can figure it easily enough. The ISA bus supports a maximum address range of 16MB, though a small amount of that is always taken up by the motherboard. Some PClones are expanded via custom daughterboards, for which you'd have to examine the specifications. If they're expanded instead by banks of SIMM modules, keep in mind that for PC SIMMs, the largest available with the standard parity support is 4MB. If you axe the parity like Apple did on all but the IIci, you get 16MB. That's a total of either 16MB or 64MB per 32 bit wide bank. >The Mac can access 128MB of RAM *NOW*. What can the Amiga do now? 16MB SIMMs are just barely available. Zorro III memory boards for the Amiga 3000 haven't yet been announced. The only announced product for expansion beyond 18MB for the A3000 is a 64MB expansion card from a German company that sits in the Coprocessor slot. So I guess, today, you're limited to 90MB today, from off the shelf boards. Though not announced, there are in fact a couple of Zorro III boards on the way from third party companies. The point being, it's possible to have that much RAM in an A3000, so you will eventually have a way to do it. It is impossible in most other systems, no matter what kind of add-on doohicky someone comes up with. > (Steve Kosloske) | "When the bottle's empty, the -- Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests" {uunet|pyramid|rutgers}!cbmvax!daveh PLINK: hazy BIX: hazy "This is my mistake. Let me make it good." -R.E.M.