Abstract: A display system having a scanned CRT provides a full screen layout of alphanumeric characters and at least one additional screen layout, e.g. a split screen layout.A refresh buffer stores data to be displayed in a first sequence of addresses so that when this data is read out by address generator in the first sequence a full screen layout results. A read only translation store may be selectively addressed by the first sequence of addresses to provide a modified sequence of translated addresses. When the refresh buffer is addressed by the sequence of translated addresses, a split screen layout of the data results. A selector is operable to address the refresh buffer with either the first sequence of addresses or the sequence of translated addresses.Logic inhibits character display in a blank area between the two halves of the split screen. Attribute decode logic enables different attributes to control screen halves during split screen operation.

Abstract: A display system is described in which left to right or right to left mode may be displayed without character inversion. A read/write store is added between a display buffer and a CRT. This store stores one complete scan line of character slice bytes in sequence. The bytes may be read out either in a normal sequence or in a reversed sequence for display. As bytes are read in parallel, the orientation of individual characters is unchanged.One line of control data or selected lines may always be displayed in left to right mode, while the remainder of the display is in right to left mode.