Howdy,
I was using radare2 to look at the Mac 128k ROM from here (
https://archive.org/details/mac_rom_archive_-_as_of_8-19-2011) - checksum 28ba61ce, just to get an idea how it works on the inside.
The one that is labeled as 128K, though, seems to use the Mac 512k memory map - 0x7fd00 for the sound buffer (see the instruction at offset 0x1f8) - rather than the 128K memory map - 0x1fd00 for the sound buffer. (Similarly, at offset 0x102, the ROM is using 0x7a700 for the video buffer instead of 0x1a700.) Is it really a 512k ROM and not the 128k? Or is it designed to work on both? I've seen the same ROM checksum labeled in a couple different ways. I was expecting it to match the memory map info for the 128k that is visible here:
http://www.osdata.com/system/physical/memmap.htm#MacPlus
Any suggestions to make sure I'm looking at the right resources are greatly appreciated.
Aaron
