Special teacher's version of the TI-73 has an extra port to connect to TI's LCD panel for overhead projectors or to the TI Presenter video interface. This middle grade graphing calculator has fraction functions of the TI-12 Math Explorer. Electronically upgradable. Stat plots, pie charts, metrics, trig, logs, 32Kb RAM plus 64Kb custom application memory. List-based stat and graphing. 96 x 64 dots. CBL/CBR compatible.