Browse Prior Art Database

Raster Display Blink Mechanism

IP.com Disclosure Number: IPCOM000039036D
Original Publication Date: 1987-Apr-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 3 page(s) / 73K

Publishing Venue

IBM

Related People

Malden, AE: AUTHOR

Abstract

A raster display consists of a display generator and a display monitor. A common console may contain two displays, a main display and an auxiliary display. These are driven by a resident processor called a sector processor. Fig. 1 shows the configuration of a common console. (Image Omitted) The common console main display consists of: 1. Display generator 2. High resolution monitor 3. Manual input devices (including the positional entry device, the interactive display and the keyboard) 4. Sector processor with dual interfaces and an interface to the display generator. The display generator contains the vector generator, symbol generator, cursor generator, refresh memories for the main and auxiliary displays and the control logic to handle I/O, and manual inputs.

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Raster Display Blink Mechanism

A raster display consists of a display generator and a display monitor. A common console may contain two displays, a main display and an auxiliary display. These are driven by a resident processor called a sector processor. Fig. 1 shows the configuration of a common console.

(Image Omitted)

The common console main display consists of: 1. Display generator

2. High resolution monitor

3. Manual input devices (including the positional

entry device, the interactive display and the

keyboard)

4. Sector processor with dual interfaces and an

interface to the display generator. The display generator contains the vector generator, symbol generator, cursor generator, refresh memories for the main and auxiliary displays and the control logic to handle I/O, and manual inputs. A block diagram of a display generator with one refresh memory is shown in Fig. 2. The output of each refresh memory is used to address a programmable lookup table. The monochrome display generator will take each pixel value (nominally four bits) and use this to address the lookup table. An exemplary application requires six brightness categories, three data intensities, four blink rates, steady display and off. This requires 15 conditions for each pixel, which can be represented by a four-bit code. This analysis assumes that blinking data blinks at a predetermined intensity level independent of the intensity level with which it was displayed when not blinking. (If this assumption is not correct the number of bits per pixel would increase from four to six.) Fig. 3 shows a simplified lookup table with two address bits and six data bits. This might be used in a raster display with two intensity levels and one blink rate (although the actual rate would still be changeable under program control). The output from the lookup table will be a six-bit code (the exact number of bits will be determined by the speed, cost of D/AS and the ability of the operator to perceive incremental changes in the programmed brightness level). This code will be used to address a six-bit D/A converter. Operator intensity adjustment for the six display data categories and the three data levels will be accomplished by having the sector processor modify the lookup table contents in the display generator. For a color display, the lookup table can be expanded to provide six bits to each of three D/A converters, one for each primary color, each of which would be gated by the blink conditions, as above. The lookup table is modified during vertical retrace. The lookup table memory, shown in Fig. 2, contains the data used to modify the lookup table. The transfer of data from the lookup table memory to the lookup table is initiated at the proper time by the controller. During the time

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intervals when blinking data is not to be to displayed, the lookup table will contain data causing t...