IBM Journal of Research and Development
IBM Skip to main content
  Home     Products & services     Support & downloads     My account  

  Select a country  
Journals Home  
  Systems Journal  
Journal of Research
and Development
    Current Issue  
    Recent Issues  
    Papers in Progress  
    Recent publications  
    Author's Guide  
  Contact Us  
  Related links:  
     IBM Research  

IBM Journal of Research and Development  
Volume 28, Number 4, Page 379 (1984)
Nontopical Issue
  Full article: arrowPDF   arrowCopyright info


All points addressable raster display memory

by R. Matick, D. T. Ling, S. Gupta, F. Dill
This paper discusses display designs which store the image point by point in random access memory, so that independent update of every pixel is possible. A frequent bottleneck in the design of high performance displays of this type is the available bandwidth of the memory subsystem. In this paper, we focus on this issue and present features of a customized dynamic RAM chip which can readily provide the necessary bandwidth and thus greatly simplify the design of very high performance APA raster scan displays. The customized RAM chip is quasi-two-ported. After briefly introducing APA raster displays, we discuss display memory system design and the design of the proposed custom memory chip. We describe the second port for the video refresh, which makes the primary port available for update almost continuously. We also discuss modifications to the existing primary port to make it easily usable for the parallel update required for high update performance as well as for other applications.
Related Subjects: Display technology; Graphics; Memory, random-access