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Video System With Real-Time Multi-Image Capability and Transparency

IP.com Disclosure Number: IPCOM000036337D
Original Publication Date: 1989-Sep-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 2 page(s) / 58K

Publishing Venue

IBM

Related People

Flurry, GA: AUTHOR [+3]

Abstract

The architecture described herein allows storage and retrieval of multiple images within a single physical memory array, and the ability to display portions of these images simultaneously at normal display refresh rates or in real time. This architecture, which is shown in Fig. 1, also allows simultaneous access to the memory array while performing real-time CRT refresh.

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Video System With Real-Time Multi-Image Capability and Transparency

The architecture described herein allows storage and retrieval of multiple images within a single physical memory array, and the ability to display portions of these images simultaneously at normal display refresh rates or in real time. This architecture, which is shown in Fig. 1, also allows simultaneous access to the memory array while performing real-time CRT refresh.

The address generation block converts a 19-bit linear address field into the required row and column address, and it also generates the control signals to the memory array. The selection and serialization block uses the mode bits to correctly set the clock rates and the

(Image Omitted)

scan line length for the various image formats which are supported by the system. This includes 640 X 480 uncompressed, 320 X 480 horizontally compressed, 320 X 240 double diagonal grid and 640 X 240 vertically compressed images. Since there are two banks, two images can be stored, and these images can be of differing formats, as indicated by the mode contol bits. It is therefore possible to shift two images out of the memory array simultaneously and to combine them in some manner prior to display.

This system also supports programmable transparency for each of the images to be displayed. Transparency means that any color in the image can be deemed transparent, and that the color in the underlying image will be displayed instead. This is analagous...