DOCUMENT NUMBER Efc
qa.wi g . p ii 1e151 6 83 qa.wi g . p ii 1e151 6 83 As previously mentioned, there are two types of graphics that can be displayed on the television screen playfield graphics and player missile graphics. Playfield graphics are always generated by a process known as direct memory access or DMA. There are four playfields, each identified by its own color luminance register. Playfield is generated by two playfield DMA techniques character map and bit map. Player missile graphics can be generated...
DOCUMENT NUMBER Qfz
The CGIA uses direct memory access to accomplish several different functions. The primary function is to fetch display instructions and playfield graphics data from memory for display. The secondary function is to fetch player missile graphics data for display. All aspects of DMA are controlled by the DMA control register. The DMA control register can enable disable display instruction fetches, as well as, playfield graphics data fetches, select one of the three playfield display widths, enable...