From the picure at https://dl.dropboxusercontent.com/u/55419307/DEC%20Rainbow%20100/Rainbow%20Mainboard%201.jpg
Is that motherboard a DEC Rainbow 100A or 100B?
Does the character generator rom have any different marking on 100A vs 100B?
Do you know what the 23-xxxEx markings are for the main cpu roms for both 100A and 100B?
Is the chargen.bin in the driver dumped from the 23-037E3 chip or another chip?