thietkerem wrote:The New Generation Rom that is allowed to use in SheepShaver Win is for the green iMacs. The green iMac ant other New Generation macs has NO FLOPPY. You cannot boot from a FLOPPY in SheepShaver Windows. If you can (I don't know) to burn a disk tools image on a CD, you will can.
Interestingly, even though the iMacs didn't come with floppy drives, the New World ROMs were embedded in the system file and were not targeted at a specific hardware platform. That's what made them different from Old World ROMs that were in physical Read-Only memory soldered on to the machine motherboard.
Essentially, the New World style had an Open Firmware image in the EEPROM that contained a Forth interpreter that could load instructions off a disk, and that's about it. Everything else was integrated into the ROM file and read off during boot.
The other interesting bit is that even though New World ROMs only targeted PowerPC devices, the high addresses on the ROM are actually the Mac Plus 68k ROM. This means that if everything else fails to work, the OS/OF combo could always fail back to the Mac Plus hardware description even though it didn't have much in common with the PowerPC Macs that could run the OS.
SheepShaver takes advantage of some of these shenanigans by patching the ROM address (whether loaded from the Old World dumped ROM image or the New World ROM file) to provide direct host functions instead of those referenced in the ROM for things such as storage peripherals, memory, video, keyboard and mouse.
As a result, when you use a ROM with SheepShaver, this doesn't really emulate the machine that the ROM is associated with, but purely uses the ROM scaffolding as a way to address the real and virtualized hardware on your machine. This allows you to have configurations that never actually existed in real Apple hardware. The ROM image just has to have all the toolbox calls available that are required to run the OS that's booting within SheepShaver.