Subject: Re: Sirius Ram and ROM 00 Question . . . . Newsgroups: comp.sys.apple2 From: dempson@actrix.gen.nz (David Empson) Date: Thu, 29 Apr 1999 02:21:08 +1200 Message-ID: <1dqzubc.y8kd6q9ltjdcN@dempson.actrix.gen.nz> References: <7g27r9$oeo$1@nnrp1.dejanews.com> Organization: Empsoft X-Newsreader: MacSOUP 2.3 NNTP-Posting-Host: 202.49.157.176 X-Trace: 29 Apr 1999 02:19:33 NZST, 202.49.157.176 Lines: 60 Path: lobby!newstf02.news.aol.com!portc01.blue.aol.com!newsfeed.direct.ca!su-news-hub1.bbnplanet.com!lsanca1-snf1!news.gtei.net!news.netgate.net.nz!news.xtra.co.nz!news.iprolink.co.nz!news.actrix.gen.nz!dempson wrote: > I have an older GS which boots up with a ROM 01 message, but > it only has 256K of built-in RAM. Is this what I have heard > referred to as a ROM 00 GS? No. A ROM 0 IIgs doesn't display any copyright message or ROM version on the startup text screen - just "Apple IIgs" at the top. ROM 0 is the original firmware that was shipped with the IIgs in September 1986. ROM 01 was available as an upgrade (single ROM swap) in 1987, and machines from then until 1989 were shipped with ROM 01 preinstalled. (After 1989 came the 1 MB motherboard, which contains ROM version 3.) > Also, I recently purchased a Sirius RAM card with 8 megs. > There is a dip switch setting to choose between "1024K" and > "256K". That will be to select the size of SIMMs which are installed on the card itself. The OctoRAM card (which I have in my ROM 1) has a similar setting. It has nothing to do with the amount of RAM on the motherboard. Assuming the Sirius card supports the same configurations as the OctoRAM, you should be able to install 1, 2, 4 or 8 of the same type of SIMM: all must be 256KB, or all must be 1MB, and the size jumper must be set accordingly. If you have eight 1MB SIMMs installed on the card, this jumper must be set to the 1024K position. > Setting up the dip switches for 1024K and 8 megs on the card resulted in > the system hanging just prior to reaching the finder when booting a GS/OS > 6.0.1 floppy. This is the correct setting, so it sounds like a fault with your motherboard, with the memory card, or perhaps one or more of the SIMMs installed on it. > Is my particular GS ROM incapable of supporting more than > 2 megs of additional RAM? Every version of the IIgs motherboard (and firmware) can support 4MB of expansion RAM without the card doing anything special. To support more than 4MB requires the card to cheat a little, but it works fine for everything except I/O cards which use Direct Memory Access. (Even then, the RamFAST SCSI card is able to use DMA with most 8MB RAM cards.) The absolute limit is 8MB of "fast" RAM, including the motherboard RAM. This means that with a ROM 0 or 01 IIgs, an 8MB RAM card will have 128KB of "wasted" memory on the card, while a ROM 3 IIgs with an 8MB RAM card will have 1MB "wasted". -- David Empson dempson@actrix.gen.nz Snail mail: P.O. Box 27-103, Wellington, New Zealand