How the requirements are met. Infrared port allows activation of all features remotely. Only software protocol needs to be added. No cost to use standard signal levels. Keys do not require contact with human body to work.
Dished keys make it easier to press keys for people with limited manipulation.
Headset jack is a TTY connector - Headset jack already used as TTY connector today for some TTYs. Implementation with the button is preferable. The cost for the extra button is in the cents range if done as part of the overall original keyboard design. H133E50002, H133A60030, and H133E980008. The opinions contained in this course are those of the grantee and do not necessarily reflect those of the Department of Education.