It was developed by Nippon Electric Company (NEC) in order to support the Kanji character set efficiently, which explains why the APC computer line had superior graphics compared to competing models.
[6] The N5200 sported a 5 MHz Intel 8086 processor on a 16-bit bus, and came with a text-only display board using a μPD7220 (in text mode).
In 1981, an English language paper written in 1980 by Tetsuji Oguchi, Misao Higuchi, Takashi Uno, Michiori Kamaya and Munekazu Suzuki was published in the IEEE.
[8] While most computers used memory mapped character, or bit-mapped displays, those with a μPD7220 had access to a, for the time, sophisticated graphics co-processor.
The large memory space, combined with hardware viewport registers permitted smooth high-speed scrolling.
In this way, bitmaps could be Blitted around the display at high speed and the controller kept focused on the more complex rendering tasks.
It included a light pen interface that synchronised the pixel clock to input signals without additional processor support.
A few years after its introduction, one journalist said "The 7220 GDC chip is a component that even some of NEC's competitors have found too good to pass up.