A bitmap memory bank which allows block accesses

Abstract

AbstractAlong with the development of high‐density memory devices (Mbit DRAM), there have been many studies on how to manage two‐dimensional binary data by employing a bitmap method. A special purpose, memory bank for systematically managing bitmap data has been produced. It can be used for various purposes, not only for bitmap CAD but for enumerating binary or gray images expanded on a bitmap editor. In order to transfer bitmap data on the scale of a few Mbits within a practical time, the memory bank executes an access of bitblt method using special purpose hardware for addressing, memory accessing, and bitwise operations. In this study the hardware consists of TTL, PAL, RAM, a custom LSI DRAM controller chip and a custom LSI bit operation chip. The system has a programmable sequencer which makes access from MS‐DOS possible. The memory access rate is 20 Mpixel/s in the case that extended regions are transferred while refreshed and logical operations are being performed.