Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!decwrl!uunet!orca!javelin.sim.es.com!blgardne From: blgardne@javelin.sim.es.com (Blaine Gardner) Newsgroups: comp.sys.amiga.misc Subject: Re: Few questions/observations about the A3000 Keywords: KS 2.0 Message-ID: <1991Apr24.214121.4631@javelin.sim.es.com> Date: 24 Apr 91 21:41:21 GMT References: <1991Apr22.184252.10274@bronze.ucs.indiana.edu> <1991Apr23.143421.17738@javelin.sim.es.com> <1991Apr24.172714.462@daffy.cs.wisc.edu> Reply-To: blgardne@javelin.sim.es.com Organization: Evans & Sutherland Computer Corporation Lines: 69 pochron@cat52.cs.wisc.edu (David Pochron) writes: >In article <1991Apr23.143421.17738@javelin.sim.es.com> blgardne@javelin.sim.es.com writes: >>No disadvantages that I can see, except you give up 512K of RAM to the >>Kickstart image that's loaded from disk. The advantages to the current >>setup is you can upgrade the OS from a floppy, without having to open >>the case. Since RAM is cheap, and RAM is faster than ROM, I plan to stay >>with the disk-based Kickstart myself. >Unless I am mistaken, I don't think Commodore will be releasing a disk-based >final version of Kickstart this time around. CBM hasn't said anything one way or the other, but since all existing A3000's load KS from disk, it's at least a 50-50 chance that the final 2.0x KS will be available on disk for the A3000. Note here that the A3000 has a different KS image than the other machines (at least 1.3.x, 2.0 itself may deal with all machines with one KS), so a KS floppy for the A3000 doesn't mean that there will be a KS floppy for any other machines. But since CBM hasn't said anything, this is all pure speculation. >Furthermore, unless you have a pre-3000 Amiga with a faster CPU & 32 bit RAM, >there is no speed difference between running KS in ROM and running KS in RAM! >(I thought this was all discussed in c.s.a.h several months ago about ROM vs >RAM...) Unless you have a 32-bit CPU with an MMU, it's impossible to move KS into RAM, so how could you tell? On my A2500/20 moving KS to RAM gives about a 3.6 X speed increase to "ROM" access, quite noticable, and well worth the 256K of RAM. >I hope I am not sounding too harsh, but I just don't see any advantage to using >up 512K of precious RAM on the 3000's, + HD space, (or waiting for KS to load >from floppy, (arg!)) just to have KS in RAM when there won't be any need to. You're assuming that RAM and disk space are worth more than speed. I've got 8M of RAM and 600M of disk space, and I'll happily give up a half-meg of each to speed up the system. The time to load KS from disk is negligible (about 1-2 seconds, but it's fast enough that I've never bothered to time it), and you only need to do that from a cold boot, so that's not a factor either. The speed difference between RAM & ROM won't be as dramatic on the A3000 as it is on the A2500 because the A3000 ROM is 32 bits wide, but it's still dog-slow ROM. And 80 nS RAM is going to give you a noticable boost over 250 nS ROM (just a WAG on the ROM speed there, I don't remember it exactly). And again, we're only taking about the A3000 here, since it's the only machine that CBM has released 2.0 on. There are various tricks to let developers run 2.0 on any machine with 1M of AutoConfig RAM, but that's a developer's tool, not something fit for the general public. >(And again, any disk-based version is bound to not be as up-to-date as the >final ROM version will be.) Why? So far disk-based 2.0 Kickstarts are FAR more current than the antique KS ROM that bootstraps existing A3000's. Again, it comes down to CBM producing a floppy of the frozen 2.0 KS image. If they do, I'll run from disk, if they don't, I'll buy a ROM chip. >As for 2000 owners with 68020/30's, (like me) having SetCPU just download >the OS from ROM into 32 bit RAM is much easier than having an image of it out >on disk. If I need to use 1.3, SetCPU provides that feature already... But what about that precious RAM space you're loosing? :-) -- Blaine Gardner @ Evans & Sutherland 580 Arapeen Drive, SLC, Utah 84108 blgardne@javelin.sim.es.com BIX: blaine_g DoD #46 My other motorcycle is a Quadracer. FJ1200