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.