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Apple IIGS Variations?
- Thread starter dcr
- Start date
david__schmidt
Well-known member
Regarding motherboards: ROM0 and ROM1 shared the motherboard they could plug into. Of that compatible version of IIgs motherboard, there were two variants I know of: one had connectors populated for IIe-style power supply and keyboard (used in "stealth" IIgs cases, upgrading IIe machines) and one without those connectors populated. The ROM03 motherboard was not plug-compatible with ROM0 or ROM1 ROMs (ROM03 had twice the ROM capacity) and of course had a host of firmware and hardware changes, including more on-board RAM.
david__schmidt
Well-known member
They all fit the IIgs case. The form factor is the same among all.
Dog Cow
Well-known member
I want the ROM 4! Will it work on my ROM 4 motherboard? What am I expecting with the ROM 4 and what about compatibility? Would I be able to go straight with System interface like Mac 68k and be able to boot into DOS inside the OS directly for Apple // games? I would like to turn my Apple //gs into Mac heheh!
The only known prototype of a "Mark Twain" IIgs in existence actually identifies itself as "ROM3", so there may in fact be no such thing as finished "ROM4" ROM code.
The major difference between the "Mark Twain" motherboard and the previous versions appears to boil down to little more than the prototype having SIMM sockets instead of a memory upgrade card slot and a SCSI controller onboard. (Presumably the SCSI hardware is roughly the equivalent of the slotted "High Speed SCSI card".) My wild guess would be that the prototype probably has a near-verbatim copy of the ROM3 code (which of course doesn't buy you anything) plus the firmware for the SCSI hardware lumped into its onboard ROM so, no, it probably wouldn't work in a ROM3 motherboard, nor would you gain anything from it.
All IIgs'es can boot straight to GS/OS assuming you have compatible mass storage hardware, and there are also software solutions for encapsulating at least *some* Apple // games into bundles that can launched from GS/OS. Sort of thought that had actually been discussed at some point.
Then I'd suggest that an LC-class Mac with a IIe card would probably be a better fit for your needs.
Dog Cow
Well-known member
Is it possible the bug in ROM03 could also be the reason why so many Apple // games not working? Even a text adventure game seems to fail in my apple //gs ROM 03 but works on AppleWin emulator.
I just scanned the top posts in those threads, but what I saw there seems to verify that the "Mark Twain" source is indeed only slightly different from a regular ROM3 and had the same OS 5.x toolsets embedded in it, not updated 6.x ones?
You know what I really like is have a card you can put in any of the spare slots that have ROM01 of apple //gs and cancel ROM03 (while the card is in there) for backward compatibility being better and anytime you can disable the card by a switch behind it if you wish to return back to rom03
That is something I would buy in a heart beat.
Dog Cow
Well-known member
I only have a ROM01, but to people in the know, is there really that much difference in compatibility with "legacy" Apple ][ software? (In particular, older DOS 3.3 or proprietary-booter software that predates the IIe.) Honestly, just playing with game disks generated off the AIIdiskserver or randomly pulled from Asimov and other such sources it's my general impression that the IIgs is significantly less compatible with this sort of software than my IIc is. (Most of the game disks I make are II+ compatible; I have a II+ as well so that's my baseline.) I actually don't think I've found anything that runs on the II+ but not the IIc, but that's definitely not true in the case of the IIgs.
I am trying very hard to understand what you typed there. Sorry. I may read it again later and try to understand it, however...there are many apple // 8 bit games not working in my apple //gs ROM 03 though. Some even include text adventure games but will work instantly in appleWin Emulator.
What I am saying there is that while I AM aware that there is a small selection of Apple IIgs-specific software that runs on the ROM01 but not the ROM03 I am not aware of any differences in compatibility with 8-bit software between the two machines. (IE, so far as I know both are equally good/bad at emulating an Apple IIe.) And then I am further agreeing with you that the IIgs' backwards compatibility seems to be less then perfect regardless of which ROM version it's running because, yes, I have found a not-insigificant number of 8-bit titles that seem to work fine on my IIc (which is the hardware equivalent of an "enhanced" IIe) but fail on the IIgs, despite my IIgs having the supposedly "more-compatible" ROM01.
In short, I suspect the problems you're seeing with your text adventure game are generic problems with the IIgs' hardware compatibility that aren't going to be fixed by changing ROMs.
AH!!!!
Ok! Ah well. I guess for games that refuse to work on apple //gs and I really want to play it. I will run it in AppleWin then 
