(Although if that were important a better emulation target for vMac might be the Portable/Powerbook 100.) Although, really, if you're running something that needs more then 4MB you probably also want networking support, and that leads right down the slippery slope to Basalisk II and System 7.
the 4MB the 68000 Plus/SE/Classic machines could address. Like the first game in the series, Eschalon: Book I, it features a large and openly explorable game world, a comprehensive management of character statistics and skills, and a non-linear storyline.
It is available for free download on developer's website.
Basilisk II is an emulator of the 68k Macintosh family of computers (Macs based on Motorola 68000 processor series) that contains Macintosh, PowerBook, Performa and Quadra computers, available for Mac OS X and other systems. Released under the terms of the GNU General Public License, Basilisk II is free software, and its source code of is available on GitHub. The only possible reason I could see for wanting to do this would be that running a II-series Mac with 24 bit addressing (like System 6) would allow 8MB of RAM vs. Eschalon: Book II is an isometric, turn-based single player role-playing video game by Basilisk Games. Download and set up the Basilisk II for Mac. This is the Basilisk II Classic Mac emulator running Mac OS System 7, with SimCity 2000 and Bungie Software's Marathon. Ports of Basilisk II exist for multiple computing platforms, including AmigaOS 4, BeOS, Linux, Amiga, Windows NT, Mac OS X, MorphOS and mobile devices such as the PlayStation Portable. (However, it'll identify itself as a Mac II.) Basilisk II is distributed under the terms of the GNU General Public License (GPL). However, you still need a copy of MacOS and a Macintosh ROM image to use Basilisk II. That is, it allows you to run 68k MacOS software on your computer, even if you are using a different operating system. Within System Preferences, the Classic preference pane should appear (as shown in the screenshot above), from which you can tweak options such as whether. Upon copying OS 9s System folder over to your newer Mac, navigate to OS Xs System Preferences.
Supposedly the development snapshots of MinivMac have some rudimentary MacII emulation support( see the December 6th and various older news items) which will work with an SE/30 ROM. Basilisk II is an Open Source 68k Macintosh emulator. Tigers System Preferences should now contain the Classic pane. Once you're running on modern computers that are able to run an emulator faster than the original, I don't see any advantage in using a particular Mac's rom, other than perhaps the novelty value of ogling the About This Macintosh splash. I don't recall Basilisk II working with anything less than a 32-bit clean rom, but mini vMac will boot System 6 with a Plus rom.