The 70004A display has a removable custom hardkey panel, a key to aid in selecting the MMS instrument to be controlled, and several advanced firmware features. Up to four modular instruments can be shown on the display simultaneously. The display keyboard (softkeys and hardkey panel) controls one instrument at a time. The INSTR key lets you pass control from one instrument to another with a single keystroke. The 70004A sends displayed graphics to a HP-IB printer or plotter. It also supports the HP PaintJet printer so you can have full color printed documentation of your test results. The HP-HIL connector on the front panel allows you to attach a Keysight 46021A or 98203C HP-HIL keyboard. This can be used to control the system front panel or to enter user titles or spectrum analyzer commands and small downloadable programs (DLPs).