公开(公告)号：JPH02211521A

公开(公告)日：1990-08-22

申请号：JP3114789

申请日：1989-02-13

Applicant: IBM JAPAN

Inventor： IIDA HIROYASU ,  KODAIRA FUMIYA ,  NISHIOKA YOSHIO ,  HAYATA MASAYUKI

IPC: G06F3/14 ,  G09G5/14 ,  G09G5/30

Abstract: PURPOSE:To load the large quantity of screen attribute data by reading the screen attribute data during a horizontal display period, setting them in a register with the use of a DMA function, and preventing character data from being displayed during the horizontal display period. CONSTITUTION:A bus controller 15 accesses a DMA row starting address in a row table area by a row table address signal in the last horizontal fly-back interval during a horizontal scanning fly-back interval. According to an accessed DMA row starting address, a DMA row in a display data area 9 is read in the horizontal display interval continuously after the horizontal fly-back interval. The screen attribute data on the read DMA row are supplied to the buffer of the controller 15, and supplied to a DMA controller 17 of a display controller 16 by a prescribed timing signal. The controller 17 DMA-transfered the set data and pallet data out of the supplied data respectively to an I/O register 18 and to the memory of a pallet mechanism 19.