Our original studio control logic frame was launched in 1997, and was subsequently produced in two versions - one with two ethernet ports and eight serial ports, and a later unit with three ethernet ports and only four serial ports. Both were packaged in a 2RU frame and powered by a single 110VAC power entry.
The TallyEngine was designed around a 200-MHz ARM9 mainboard, with a four-serial-port expander and an onboard UPS which maintaned system functionality over short power outages, as well as ensuring orderly shutdown of the Linux-based onboard software.
The mix of serial versus ethernet ports was modified to match the continuing trend in the broadcast industry of migrating control structures to ethernet, while maintaining enough legacy serial capability to support re-use of existing studio hardware from undermonitor displays and stand-alone multiviewers to routers and production switchers.
Some systems were built with TallyEngine board stacks integrated into larger I/O frames to conserve rack space.