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NEC μPD7220
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NEC μPD7220
The High-Performance Graphics Display Controller 7220 (commonly μPD7220 or NEC 7220) is a video display controller and a Graphics processing unit, capable of drawing lines, circles, arcs, and character graphics to a bit-mapped display. 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. The chip was first used in the NEC N5200 and in later computers, such as the NEC PC-9801, APC II and APC III, the optional graphics module for the DEC Rainbow, the NCR Decision Mate V, the Tulip System-1, the Compis, and the Epson QX-10.
The μPD7220 was one of the first implementations of a graphics display processor as a single Large Scale Integration (LSI) integrated circuit chip, enabling the design of low-cost, high-performance video graphics cards such as those from Number Nine Visual Technology. It was one of the best known graphics chips of the 1980s.
The project was started in 1979, with trial production in 1980 and mass production starting in December 1981. It was first used in the NEC N5200 (known in North America as the NEC APC or "Advanced Personal Computer") in 1981. 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). An optional graphics-only display board, sporting a second μPD7220 chip (operating in graphics mode), "merged" the text and graphics video through an XOR port (on each of the RGB signals) in hardware. The only OS on the original NEC APC was the UCSD p-System, but CPM/86 support was added in 1982[citation needed].
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. NEC deployed the chip in other computers, such as the NEC PC-9801, and NEC's APC II and later APC III computers, and also released it to other manufacturers in Japan, starting in 1982. The same year, the 7220 was revealed in North America by NEC Information Systems, the US arm of NEC.
By 1983, it was used in other early computers, from NEC and other companies including Digital Equipment Corporation and Wang Laboratories.
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 controller could either be used as a simple character display with user defined typefaces and simultaneously as an all-points addressable graphics display.
Additionally, the controller had hardware assist features for drawing straight lines and sectors of circles. It would draw pixels along a line, a circular arc or from user defined characters in under 800 ns. This released the host computer to continue other processing while the drawing operation continued.
The high-resolution capability permitted support for glyph-based languages like Japanese that were difficult to comprehensively support with character-based displays. The large memory space, combined with hardware viewport registers permitted smooth high-speed scrolling.
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NEC μPD7220 AI simulator
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NEC μPD7220
The High-Performance Graphics Display Controller 7220 (commonly μPD7220 or NEC 7220) is a video display controller and a Graphics processing unit, capable of drawing lines, circles, arcs, and character graphics to a bit-mapped display. 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. The chip was first used in the NEC N5200 and in later computers, such as the NEC PC-9801, APC II and APC III, the optional graphics module for the DEC Rainbow, the NCR Decision Mate V, the Tulip System-1, the Compis, and the Epson QX-10.
The μPD7220 was one of the first implementations of a graphics display processor as a single Large Scale Integration (LSI) integrated circuit chip, enabling the design of low-cost, high-performance video graphics cards such as those from Number Nine Visual Technology. It was one of the best known graphics chips of the 1980s.
The project was started in 1979, with trial production in 1980 and mass production starting in December 1981. It was first used in the NEC N5200 (known in North America as the NEC APC or "Advanced Personal Computer") in 1981. 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). An optional graphics-only display board, sporting a second μPD7220 chip (operating in graphics mode), "merged" the text and graphics video through an XOR port (on each of the RGB signals) in hardware. The only OS on the original NEC APC was the UCSD p-System, but CPM/86 support was added in 1982[citation needed].
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. NEC deployed the chip in other computers, such as the NEC PC-9801, and NEC's APC II and later APC III computers, and also released it to other manufacturers in Japan, starting in 1982. The same year, the 7220 was revealed in North America by NEC Information Systems, the US arm of NEC.
By 1983, it was used in other early computers, from NEC and other companies including Digital Equipment Corporation and Wang Laboratories.
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 controller could either be used as a simple character display with user defined typefaces and simultaneously as an all-points addressable graphics display.
Additionally, the controller had hardware assist features for drawing straight lines and sectors of circles. It would draw pixels along a line, a circular arc or from user defined characters in under 800 ns. This released the host computer to continue other processing while the drawing operation continued.
The high-resolution capability permitted support for glyph-based languages like Japanese that were difficult to comprehensively support with character-based displays. The large memory space, combined with hardware viewport registers permitted smooth high-speed scrolling.
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