Apple Lisa Booting in MESS

MESS has an Apple Lisa emulator in it, but it is not complete and therefore will not boot the Lisa Office System. It will boot MacWorks, but nothing else. Nathan Lineback's GUI Gallery has his images of MESS attempting to boot various Lisa operating systems; here are mine. I have gotten the Lisa OS to boot into MESS as far as it can possibly go, which is a little farther than what he has. I have also done enough research that I know what the emulator is failing on and why the Lisa OS refuses to boot.

The Lisa emulator starts up.

The first error message we encounter in the Lisa's self-test. The number 42 indicates a problem with the serial port. This isn't so bad, as far as I know; it just means we couldn't use LisaTerminal. Instead of going right to Startup From, we can choose Continue.

The Lisa emulator continues its self-test. It takes quite a while to scan the RAM in emulation.

The second error message. Number 55 indicates a problem with video. Unlike the serial port problem, this one is critical and ultimately the reason Lisa OS won't boot. We can still choose Continue.

At this point we reach the Startup From menu where we can choose a disk to boot from. The disk drive MESS provides is #2.

I actually was able to feed it a Lisa disk in the right format. From this screen, it appears as if the emulator is attempting to boot up the Lisa OS!

Nathan Lineback's site has a screen shot of error 23, which means the disk is not in the right format.

Unfortunately, this is as far as it can possibly go, and we crash with this weird 10201 error; this code is undocumented, and most likely doesn't mean anything specific.

Now, the reason why the Lisa OS will not boot in the MESS emulator has to do with its strange copy-protection scheme. The Lisa OS ties itself to the Lisa machine it is running on, in a similar manner to the individual tools. The Lisa actually incorporates its serial number into the video stream (hence the mysterious "Video State ROM" that contains just the serial number). The Lisa OS reads the Lisa's serial number from the video stream; if it can't read the serial number, it refuses to boot. Error 55 indicates that video is not emulated properly, so the Lisa OS can't read the video stream, so it can't determine the serial number, so it refuses to boot. This is also what makes the square pixel mod and certain CPU accelerators break the Lisa OS software.

The MESS system status for the Lisa emulator says that the MMU is still buggy. The MMU certainly has its hands in accessing the video stream from software, so that is certainly part of the problem. There is no way for me to know if it's just the MMU or both the MMU and the video that are causing the Lisa OS to fail.