The tree you're barking up has fruit. I know the schematics are out there. I used to have a set, but have since lost them. I've used several 7300s. The hardware was designed by convergent technologies. It has a wonky graphics interface because of a poor choice of a monitor. There should be simple power converters to give you 120v at 60 Hz. The 7300 was used as a console for some of the AT&T PBXs, so there was a lot of them made. They had the bigest expansion slots I have ever seen, going almost the entire depth of the box, which was too deep. Key action on the keyboard was nice. The unicomp keyboad that I now use has similar action. If AT&T had put some version of Unix other than System V, there might have been life in the old girl. The UNIX PC and the DMD terminals had this myopic corporate protectionism in common. I always thought that if the DMD5620 had been cheaper and they had had OS support for BSD as well as System V, the history of computing would have been very different. I couldn't get my boss to pay $6K for a terminal when the average price for a nice terminal was $1K. If he had let me buy one, I then would have had to port the support code. Compilers, the Mux communiction protocol, all the programs that ran in the terminal, would have had to be change to run under the non-System V system that we were using at the time. AT&T's decisions during the period displayed a persistant lack of undertanding marketing. If the customer came first, they would have supported the OS customers wanted.