Display system having modified screen format or layout
First Claim
1. A display system comprising a scanned refresh display device, a refresh buffer having storage positions for data to be displayed and address generating means arranged to address the refresh buffer in a first sequence of addresses to display the data in a first screen layout, characterized by a translation store addressable by said first sequence of addresses to read out a modified address for each address of said first sequence to provide a sequence of translated addresses arranged to address the refresh buffer to display the data in a second screen layout, and selection means operable in a first mode to switch said first sequence of addresses to the refresh buffer and operable in a second mode to switch said modified sequence of translated addresses to the refresh buffer.
0 Assignments
0 Petitions
Accused Products
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.
Read only store is preferably replaced by a read/write store when several alternative screen layouts are required. Each alternative screen layout requires a sequence of translated addresses to be supplied to the read/write store from a controller.
63 Citations
9 Claims
- 1. A display system comprising a scanned refresh display device, a refresh buffer having storage positions for data to be displayed and address generating means arranged to address the refresh buffer in a first sequence of addresses to display the data in a first screen layout, characterized by a translation store addressable by said first sequence of addresses to read out a modified address for each address of said first sequence to provide a sequence of translated addresses arranged to address the refresh buffer to display the data in a second screen layout, and selection means operable in a first mode to switch said first sequence of addresses to the refresh buffer and operable in a second mode to switch said modified sequence of translated addresses to the refresh buffer.
Specification