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The 24-bit ROM Blues

I love coincidence because it generally means I've got an article for TidBITS. Luckily it seems to happen all the time in this industry. A week or two ago, Tonya got a question about the upper memory limit in the SE/30 versus the IIsi at work, and someone complained to me about SE/30 ROMs in email (can't remember why, offhand), and when I catch up on my Usenet news, I find that a brouhaha has been brewing on the Internet about ROM upgrades. People are debating the idea of new ROMs for the II, SE/30, IIcx, and IIx, though it's not so much a debate as a group yell. No one is rabid about the subject yet, since System 7.0 hasn't shipped, but as soon as people can upgrade to System 7.0, owners of the SE/30, IIcx, and IIx will be unhappy because they will be unable to address more than 16 MB of RAM (I think it drops by 13 MB of RAM that you would really be able to use because of the address space for the video and the PDS slot, though I definitely don't completely know what I'm talking about). With the price of 4 MB SIMMS dropping constantly and virtual memory in System 7.0, that limit will suddenly become a real constraint. There's nothing worse than memory limitations - I hate it when I can't remember what I'm supposed to make for dinner and I hate old PC-clones and their foolish 640K main memory limit. Jim Gaynor of Ohio State University says that the spec sheets for the SE/30-class machines advertise their ability to address up to 128M of RAM, which will only become possible with true 32-bit clean ROMs.

Jim has started a mailing list to discuss this problem and to consolidate support for the ROM upgrades. To subscribe, send mail with the body of the message being SUBSCRIBE to The list address itself is (I'm irritated when I subscribe to a list and can't figure out how to send mail to it). One interesting thing that came out of the initial discussions on Usenet is that although the SE/30-class machines all have ROM SIMMs which can be easily upgraded (and are even advertised as a feature in the spec sheets for those machines), the Mac II has socketed ROMs, which means that ROM upgrades are easy for that machine too. In fact, Apple has provided at least on upgrade for the Mac II ROMs. It had something to do with early Mac II ROMs being unable to "switch into 32-bit mode to access the EPROMs of NuBus boards that actually have 16 MB address spaces. This means that the Slot Manager would not see the board and all the calls would return an error." Thanks to Russell Davoli for that - I also remember hearing about a problem with the Mac II and Apple's 8*24 GC video board that was solved by a free ROM upgrade. Perhaps it was the same problem. A number of people expressed interest in a ROM upgrade for the Mac II as well, because of this. A Mac II with a PMMU and a ROM upgrade would be functionally almost identical to the SE/30-class machines with ROM upgrades.

I've heard people at Apple are also discussing this now, but a ROM upgrade would mean that bunch of old ROMs would start floating around just waiting for someone to make a Mac clone with them as Outbound did. Apple does not want this to happen, especially since it might screw up marketing for the new portables scheduled for this fall. (Oh, the word is that on the TV show "Night Court" a few weeks ago, the character Harry used a tiny personal computer that actually was one of the new portables. Didn't see it personally.) A number of possibilities for controlling this problem came up on Usenet, among them charging an exorbitant price and then returning the extra money when Apple received the old ROMs and tracking the upgrades and ROM returns by serial number. At least Cornell uses the price method with motherboard upgrades already. When we upgraded our SE to an SE/30, the price was about $1300 if we went with the "Apple upgrade," but if we didn't want to trade in our motherboard, the price went up to about $2400 for the "third party upgrade." It worked - we didn't to keep our SE motherboard.

Another worry inside Apple is that the Mac is all Apple has these days and Apple doesn't want to foster competition until it has another platform closer to release date, which could easily be 1993 or later. Nonetheless, it's obvious that Apple is working on new ROMs, judging from what they did with the Classic's boot ROMs (which, incidentally, contain System 6.0.3 AppleShare drivers that recognize a Macintosh running System 7.0's file sharing). Allowing a Mac to boot from ROM is good for a diskless workstation on a network, but it is also good for a small, light portable computer that could call in to a network for data storage. Combine that with the wireless technology General Magic is working on and that Apple petitioned the FCC for, and you get a very small portable that has boot ROMs and exists continually (while in range, anyway) on a wireless network for data exchange and storage. Interesting thought, but I digress. I'd settle for 32-bit clean ROMs for my SE/30 for the moment and will beg and plead for the portable later on.

Information from:
Jim Gaynor --
Russell Davoli --
Dave Barnhart -- dbarnhar@oiscola.Columbia.NCR.COM
Kent Borg -- kent@sunfs3.Camex.COM
John Price --
Matthew T. Russotto --
Chris Silverberg -- macman@wpi.WPI.EDU
John Scudder --
Paul Campbell -- paul@taniwha.UUCP
Jeff Sullivan -- jas@ISI.EDU
Tony Gedge --


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