DEMO Vidoes available at: https://sites.google.com/site/interface1bis/videos?authuser=0

The device is a functional replica of the Sinclair Interface 1, maintaining complete backwards compatibility at BASIC command and hook-code level, yet featuring considerably enhanced capabilities due to its innovative micro-controller-based architecture, solid firmware and time-tested operating system.

The ‘Interface 1bis’ is designed to connect directly to the expansion port of original Sinclair or Amstrad ZX Spectrum computers or a Sinclair Interface 1.

Unlike most ZX Spectrum add-ons, the IF1bis does not perform hardware trapping and can function even if the host machine's CPU has a faulty /M1 line.