Abstract: The computer terminal controller makes it possible to operate a relatively large number of input-output terminals with a single mainframe computer. The controller has a basic configuration enabling it to control up to sixteen terminals. However, the user easily can increase its capacity by adding one or more expansion modules, each module consisting of a cable connector panel and a printed circuit card. Precise locating pins and support structure and hand-operable fasteners are used to mount the panel so that no tools or special skills are needed. Each circuit card preferably contains sufficient circuitry to handle a specific number of additional input/output terminals, and the panel has the same number of cable connectors. The card and the panel are connected to one another by simply plugging them together. The card is guided accurately into engagement with the panel by card guides.

Abstract: This invention provides improved means for automatically retracting the styli away from the paper when the rotational speed of the rotor drops below a predetermined minimum level. Improved means also are provided for stably holding and accurately positioning the styli during printing. In addition, simple means are provided for adjusting the axial position of the styli to ensure proper character spacing. A snap-on housing protects the rotor and the retracted styli and allows the rotor and styli to be removed easily from the rotary printer as a single enclosed unit. An improved latch is provided for locking the rotor in one place on the drive shaft, but allowing the rotor to be removed relatively easily. The platen has a slight inclined area or ramp at the leading edge of the recording paper. The ramp smooths the travel of the styli on to the paper and increases the area of the paper which can be used for printing.

Abstract: The printer records images in the form of dots on electrical discharge-sensitive paper. Three groups of five styli are mounted on a rotor. The paper is in strip form and is fed continuously through a curved guide in a direction perpendicular to the plane of rotation of the rotor, so that the paper is wrapped part way around the rotor as it moves past. Characters are formed from a five dot by seven dot matrix. This invention provides means for automatically retracting the styli away from the paper when the rotational speed of the rotor drops below a pre-determined minimum level and, of course, when the rotor stops. This facilitates removal of the rotor from the printer, and also facilitates feeding a new strip of paper into the printer. Means also are provided for adjusting the axial position of each group of styli merely by turning one or more screws. The screws are easily accessible without removing the rotor.