egretrom-1.0.3.zip (info) a zipped hfs disk image and checksum file. The disk image can be mounted with Mini vMac. Includes source code.
egretrom-1.0.3-sit.zip (info) The same contents, repackaged as zipped Stuffit archive.
EgretRom is a utility to write out to an image file a copy of the ROM of the Egret microcontroller used to manage power in some Macintosh models. It was made at the request of Arbee (AKA R. Belmont), to assist the MESS emulator project.
It was made from Arbee's specification, and he reports that the "second version works fine and has been used to dump Egret/Cuda/Caboose ROMs on everything from '030s to G3s". (I don't have the hardware to test it myself.)
The MESS "Mac Technical Notes" document some Macintosh models that contain Egret and Cuda.
To use, just launch the EgretRom application. It should write out a file named "Egret.ROM" (to the folder containing the application) and then immediately quit.
On a machine without an Egret microcontroller, EgretRom may or may not detect that, and give an error message. (If it doesn't, a crash is likely.)
EgretRom can be used even on a machine without a working keyboard, mouse, and/or screen. This can be done by preparing a floppy disk with EgretRom set to be the startup application (in System 6 or earlier, not System 7), and replacing the finder with the "AutoQuit" application. Make sure there is enough free disk space for the ROM image file.
The ROM image files that EgretRom saves are copyright Apple Computer, and may not be redistributed.
See the Compiling page for instructions on compiling EgretRom from the source code.
You can redistribute EgretRom and/or modify it under the terms of version 2 of the GNU General Public License as published by the Free Software Foundation. See the included file COPYING.
EgretRom is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the license for more details.
January 7, 2012 version 1.0.3 - Arbee reports that the Egret ROM is even larger on some more machines.
December 19, 2011 version 1.0.2 - Arbee reports that the Egret ROM is larger on some machines.
October 24, 2010 version 1.0.1 - Arbee reports that 6805 address argument to _EgretDispatch should be 16 bits, not 32 bits.
October 23, 2010 version 1.0.0 - initial release.
If you find EgretRom useful, please consider helping the Gryphel Project, of which it is a part.