I'm reading about the Automatic Intercept System as discussed in BSTJ Vol. 53 No. 1 this evening. It is a stored program control call handling system designed to respond to calls with potential forwarding or disconnection messages. Reading through the description of the operating system for AIS got me wondering: What with the growing experience in the CSRC regarding kernel technologies and systems programming, was there ever any crossover regarding UNIX folks applying their developments to other non-UNIX AT&T systems projects or vice versa, perhaps folks who worked primarily on switching and support software bringing things over to the UNIX development camp? In other words, was there personnel cross-pollination between Bell System UNIX programmers and the folks working on stuff like AIS, ESS switching software, etc.? Or were the aims and implementation of such projects so different that the resources were relatively siloed? I would imagine some of these projects were at least developed using UNIX given the popularity and demands of PWB. That's just my hunch though, some BSTJs also describe software development and maintenance taking place on S/360 and S/370 machines and various PDPs. Indeed the development process for AIS mentioned above, as of late 1971, involved assembly via S/360 software and then system maintenance and debugging via an attached PDP-9. - Matt G.