Yes, the G-15 was definitely a digital computer, but I'm not aware that it had any "add-on analog element," at least not any that was a standard Bendix product. There was a differential analyzer, the DA-1, that attached to the G-15 and used some of its drum memory lines for storage, but it was a digital differential analyzer, not an analog one.
There was a connector on the back of the G-15 cabinet to which a user could attach data collection equipment, but this, too, was digital -- the external signals were made available in a one-word "Input Register" the G-15 could enable, disable, and read, but any A-to-D had to be done by the external interface to the system. As to the G-15 being a personal computer, I think it was pretty much in the same league as the LGP-30 in that respect. They had similar electrical and floor-space requirements, and their costs were not all the different, either. It was definitely a single-user system, and my impression is that the G-15 was typically operated by the people programming it. Its design was not conducive to closed-shop operations. There was at least one person who used a G-15 as their personal computer -- Harry Huskey, the designer. Apparently the deal he made with Bendix to do the design included him receiving a G-15 for his personal use.
