公开(公告)号：CA1294380C

公开(公告)日：1992-01-14

申请号：CA563038

申请日：1988-03-31

Applicant: IBM

Inventor： HARRISON ROY B ,  BUTLER NICHOLAS D ,  BOWATER RONALD J ,  NORRIS PAUL W

IPC: G06T1/60 ,  G09G5/393 ,  G09G1/16

Abstract: UK9-87-008 DISPLAY SYSTEM The present invention relates to a display system comprising a display buffer 36 data indicative of picture elements with a facility for moving an image from a source to a destination position by manipulating the data in the display buffer. The present invention provides this facility by having means for reading, processing and Storing bursts of display buffer words. In the described embodiment of the invention control logic 44 first causes a burst of display buffer words containing bytes representative of the image in its source position to be read out from the display buffer. These words are passed through a barrel shifter 66, where the word is rotated as necessary and stored in appropriate byte locations in a FIFO buffer 68. The FIFO buffer has the capability to write to two word addresses simultaneously so that data words are created in the FIFO buffer which contain data in the correct alignment for writing unmodified into the corresponding display buffer words. When the source has been completely read or the buffer is full (whichever comes first) the display adapter automatically switches from reading to writing and stores the burst of data words it has in its FIFO buffer into memory at the destination locations.

公开(公告)号：CA1241780A

公开(公告)日：1988-09-06

申请号：CA483259

申请日：1985-06-05

Applicant: IBM

Inventor： BOWATER RONALD J ,  DAVIS MICHAEL I ,  FARR ROBERT W E ,  POWELL COLIN V

IPC: G06G7/163 ,  G09G5/06 ,  G09G3/00

Abstract: The specification describes a method of storing alphanumeric characters (including special symbols) in a graphics display terminal comprising a raster-scan display device and a refresh buffer including a plurality of bit planes (1 to 6) each having a respective bit storage location corresponding to each addressible pel position on the screen of the display device. In the method, a first bit plane (luminance plane 1) stores high resolution luminance data defining alphanumeric characters each as a selection of "on" bits within a respective n x m array (character box) where n is the width of the character box in the scan line direction, and at least one further bit plane (attribute plane 2) stores low resolution colour data for the characters. The attribute plane (2) comprises a respective n-bit set of storage locations which corresponds to each n-bit wide by one pel deep portion of a character box in the luminance plane (1) and defines at least the colour and/or intensity of the foreground and background of the character for the width of the character box in respect of a single scan line. The specification also describes a graphics display terminal in which data in the luminance and attribute planes may be selectively decoded either as alphanumeric data stored as above, or as bit-mapped graphics data.

公开(公告)号：DE3379004D1

公开(公告)日：1989-02-23

申请号：DE3379004

申请日：1983-06-30

Applicant: IBM

Inventor： BRESENHAM JACK E ,  BOWATER RONALD J ,  GAY ADRIAN C ,  SHEEN NORMAN R

IPC: G09G5/32 ,  G09G1/10 ,  G09G5/24 ,  G09G1/16

公开(公告)号：CA1224290A

公开(公告)日：1987-07-14

申请号：CA455228

申请日：1984-05-25

Applicant: IBM

Inventor： BRESENHAM JACK E ,  BOWATER RONALD J ,  GAY ADRIAN C ,  SHEEN NORMAN R

IPC: G09G5/32 ,  G09G1/10 ,  G09G5/24 ,  G09G1/16

Abstract: METHOD OF STORING CHARACTERS IN A DISPLAY SYSTEM In a method of storing characters in a display system having a display device with an orthogonal matrix of addressable points, each character is represented as a succession of strokes each constrained to lie in one of the eight fundamental directions of the matrix and, except for the first stroke, each starting at the end of the previous stroke. Each such stroke is stored in a binary coded form which includes a first binary number (direction code) defining the angular direction of the stroke, a second binary number (length code) defining a number of matrix steps from one addressable point to the next along the stroke in that direction, and a third binary number (move/draw code) defining the visibility of the stroke. In order to facilitate character rotation by any multiple of 45.degree. the direction code defining each fundamental direction corresponds to the addition modulo 2n of a binary constant to the direction code which defines the fundamental direction at 45.degree. thereto in a given direction of rotation, where n is the number of bits in the direction code.