Abstract: A font cartridge extrender into which a commerically available font cartridge can be plugged and which plugs into the font cartridge receptacle of a computer printer. The extender includes a novel latching mechnism which attaches the font cartridge to the extender so that the assembly can be conveniently plugged into, and unplugged from, the printer as a unit. The font cartridge is secured to the extender by a spring hook mechanism, which resides in a chute molded into the inside of the top portion of the casing of the extender. The spring hook mechanism is supported in the chute by braces and a pin molded inside the case which is inserted through an aperture in the spring hook mechanism. The spring hook mechanism is actuated by finger pressure on a contact surface.

Abstract: A system for controlling and displaying the printing format of dot matrix printers includes a microprocessor, a memory which is loaded with programs from replaceable software cards, and a control panel having a plurality of control buttons, an aligned display, and a rotary control coupled to the microprocessor. In a first mode, depression of a selected control button accesses the corresponding one of the parameters of the most commonly used print parameters and repeated actuation of the selected control button cycles through the options contained within the parameter, the parameter and current option being sequentially presented on the display. In a second mode under microprocessor control, each one of the parameters in a printing parameter menu is sequentially accessed and rotation of the rotary dial provides scrolling through each option contained within the parameter. Sets of selected parameter options can be saved under specified designations for later retrieval and use.