Abstract:
Time multiplexed signal communications between a host computer and subordinate data processing terminals include coded and noncoded information. Coded information originated by the host includes entry-separation marker signals. Individual marker signals are used at terminals to control access to associated particular time spaces of the multiplex frame. The host signals are serially stored by addressed terminals in the time sequence of transmission. The stored marker signals are protected from modification at terminals and control write-in access to storage spaced allocated to the associated time segments; thereby controlling terminal editing operations. Edited information in unprotected terminal storage spaces is easily segregated -- e.g., for compact transmission to the host -- by reference to the stored marker signals. When the non-coded signals comprise raster scanned picture information displayable at terminal display apparatus the markers are used to generate cursors indicating edit-accessible positions (e.g., character entry spaces). A distinct displaced cursor provides unique indication of the space next accessible for entry in a normal keying (i.e., typing) sequence.
Abstract:
Multiple terminals linked to one broadband cable in a sequence are interrogated by directionally coupled configuring signals and service polling signals. Configuring signals are utilized to permit selectively participating terminals to order themselves into service polling groups. Service polling signals offer successive terminals in a polling group exclusive access to a facility shared by all terminals of the group (e.g. time or frequency channel on the cable) which has not been seized by a preceding terminal of the group. Isochronal feedback shifting techniques are employed in the configuring and polling selection processes. Participating terminals progressively attach supplementary signals to the configuring and service polling signal trains ''''on-the-fly'''', without otherwise modifying or delaying the trains, by isochronally matching the signals of the passing train, extrapolating the supplementary signals and transmitting the supplementary signals immediately behind the end of the passing train through appropriate directional transmission coupling to the cable.