The D7220AD graphics chip in NMOS technology, was mounted on some DEC stations, including the DEC Rainbow 100, NCR DMV.

Features :

Microprocessor Interface

• DMA transfer with 8257 or 8237 controllers
• FIFO Command Buffering

Dispaly Memory Interface :

• Up to 256k words of 16 bits
• Read-Modify-Write (RMW) Display ;emory cicles in under 800ns
• Dynamic RAM refresh cycles for nonaccessed memory

Light Pen Input

External video syncronization mode

Graphics mode

• Four megabit, bit- mapped display memory

Character mode

• 8k character code and attribute display memory

Mixed Graphics and Character Mode

• 64k if all characters
• 1 megapixel if all graphics

Graphics Capabilities

• Figure drawing of lines, arc/circles, rectangles and graphics characters in 800ns per pixel
• Display 1024 by 1024 pixels with 4 planes of color or grayscale
• Two independently scrollable areas

Character Capabilities

• Auto cursor advance
• Four independently scrollable areas
• Programmable cursor height
• Characters per row : up to 256
• Characters row per screen : up to 100

Video Display format

• Zoom magnification factors of 1 to 16
• Panning
• Command settable video raster parameters

Technology

• Single +5v NMOS 40-in DIP

DMA Capability

• Bytes or word transfers
• 4 clock periods per byte transferred