Here is a little more information about the setup inside of the Accupath 1000:
There are three ROMs between the main board and floppy controller board. both of the ROMs on the main board are used as decoders (256x4, MMI6301) from what I can tell, while the ROM on the floppy drive controller (256x8) actually bootstraps the system.
During boot strap, nothing is show on the screen (they only have 256 bytes afterall) except the current RAM contents that the video system is using. The ROM seeks an image off of the floppy drive, loads it to RAM, and jumps to it. I will get this ROM dumped and disassembled soon.
The floppy disk drive is a Qume Qumetrak 542. After disassembling the ROM, I hope to be able to load some sort of monitor via floppy disk.