The Hercules Graphics Card (HGC) is a computer

graphics controller A graphics card (also called a video card, display card, graphics adapter, VGA card/VGA, video adapter, display adapter, or mistakenly GPU) is an expansion card which generates a feed of output images to a display device, such as a computer moni ...

made by

Hercules Computer Technology, Inc. Hercules Computer Technology, Inc. was a manufacturer of computer peripherals for PCs and Macs founded in 1982. History Hercules was formed in 1982 in Hercules, California, by Van Suwannukul and Kevin Jenkins and was one of the major graph ...

that combines IBM's text-only

MDA MDA, mda, or ''variation'', may refer to: Places * Moldova, a country in Europe with the ISO 3166-1 country code MDA Politics * Meghalaya Democratic Alliance (2018), ruling coalition government in the Indian State of Meghalaya led by National Pe ...

display standard with a

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mode. This allows the HGC to offer both high-quality text and graphics from a single card. The HGC was very popular, and became a widely supported

de facto ''De facto'' ( ; , "in fact") describes practices that exist in reality, whether or not they are officially recognized by laws or other formal norms. It is commonly used to refer to what happens in practice, in contrast with ''de jure'' ("by la ...

display standard Computer display standards are a combination of aspect ratio, display size, display resolution, color depth, and refresh rate. They are associated with specific expansion cards, video connectors and monitors. History Various computer displa ...

IBM PC compatible IBM PC compatible computers are similar to the original IBM PC, XT, and AT, all from computer giant IBM, that are able to use the same software and expansion cards. Such computers were referred to as PC clones, IBM clones or IBM PC clones. ...

s. The HGC standard was used long after more technically capable systems had entered the market, especially on dual-monitor setups.

History

The Hercules Graphics Card was released to fill a gap in the IBM video product lineup. When the

IBM Personal Computer The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first microcomputer released in the IBM PC model line and the basis for the IBM PC compatible de facto standard. Released on August 12, 1981, it was created by a team ...

was launched in 1981, it had two graphics cards available, the

Color Graphics Adapter The Color Graphics Adapter (CGA), originally also called the ''Color/Graphics Adapter'' or ''IBM Color/Graphics Monitor Adapter'', introduced in 1981, was IBM's first color graphics card for the IBM PC and established a de facto computer display ...

(CGA) and the Monochrome Display And Printer Adapter (MDA). CGA offers low-resolution (320x200) color graphics and medium-resolution (640x200) monochrome graphics, while MDA offers a sharper text mode (equivalent of 720×350) but has no per-pixel addressing modes and is limited to a fixed

character set Character encoding is the process of assigning numbers to graphical characters, especially the written characters of human language, allowing them to be stored, transmitted, and transformed using digital computers. The numerical values that ...

. These adapters were quickly found to be inadequate by the market, creating a demand for a card that offers high-resolution graphics and text. The founder of

Hercules Computer Technology Hercules Computer Technology, Inc. was a manufacturer of computer peripherals for IBM PC compatible, PCs and Macintosh, Macs founded in 1982. History Hercules was formed in 1982 in Hercules, California, by Van Suwannukul and Kevin Jenkins and ...

, Van Suwannukul, created the Hercules Graphics Card so that he could work on his

doctoral thesis A thesis ( : theses), or dissertation (abbreviated diss.), is a document submitted in support of candidature for an academic degree or professional qualification presenting the author's research and findings.International Standard ISO 7144: ...

on an

IBM PC The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first microcomputer released in the IBM PC model line and the basis for the IBM PC compatible de facto standard. Released on August 12, 1981, it was created by a team ...

using the

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, impossible with the low resolution of CGA or the fixed character set of MDA. It initially retailed in 1982 for $499.

Hardware design

The original HGC is an 8-bit ISA card with 64KB of

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, visible on the board as eight 4164 RAM chips, and a DE-9 output compatible with the IBM monochrome monitor used with the MDA. Like the MDA, it includes a

parallel Parallel is a geometric term of location which may refer to: Computing * Parallel algorithm * Parallel computing * Parallel metaheuristic * Parallel (software), a UNIX utility for running programs in parallel * Parallel Sysplex, a cluster of IBM ...

interface for attaching a printer. The video output is 5V

TTL TTL may refer to: Photography * Through-the-lens metering, a camera feature * Zenit TTL, an SLR film camera named for its TTL metering capability Technology * Time to live, a computer data lifespan-limiting mechanism * Transistor–transistor lo ...

, as with the MDA card. Nominally, the Hercules card provides a horizontal scanning frequency of 18.425 ±0.500 kHz, and 50 Hz vertical. It runs at two slightly different frequencies depending on whether in text or graphics mode, due to the slight difference in horizontal resolution.

Capabilities

Wikipedia logo displayed on a CRT monitor by a Hercules-compatible video card Simulated Hercules image at 720x348 (no aspect ratio correction) Simulated Hercules image with the correct aspect ratio (as would be seen on a 4:3 monitor) The Hercules card provides two modes: an MDA-compatible monochrome text mode, and a pixel-addressable graphics mode at 720x348. Modes: * 80×25 text mode with 9×14 pixel font (effective resolution of 720×350) * 720×348 graphics mode The text mode of the Hercules card uses the same signal timing as the MDA text mode. The Hercules graphics mode is similar to the CGA high-resolution (640×200) two-color mode; the video buffer contains a packed-pixel bitmap (eight pixels per byte, one bit per pixel) with the same byte format—including the pixel-to-bit mapping and byte order—as the CGA two-color graphics mode, and the video buffer is also split into interleaved banks, each 8 KB in size. However, because in the Hercules graphics mode there are more than 256 scanlines and the display buffer size is nearly 32 KB (instead of 16 KB as in all CGA graphics modes), four interleaved banks are used in the Hercules mode instead of two as in the CGA modes. Also, to represent 720 pixels per line instead of 640 as on the CGA, each scanline has 90 bytes of pixel data instead of 80. The 64 KB RAM of the HGC can hold two graphics display pages. Either page can be selected for display by setting a single bit in the Mode Control Register. Another bit, in a configuration register exclusive to the HGC, determines whether the second 32 KB of RAM on the HGC is accessible to the CPU at the base address B8000h. This bit is reset at system reset (e.g. power-on) so that the card does not conflict with a CGA or other color card at address B8000h.

Use

In text mode, the HGC appears exactly like an MDA card. Graphics mode requires new techniques to use. Unlike the MDA and CGA, the

PC BIOS In computing, BIOS (, ; Basic Input/Output System, also known as the System BIOS, ROM BIOS, BIOS ROM or PC BIOS) is firmware used to provide runtime services for operating systems and programs and to perform hardware initialization during the ...

provides no intrinsic support for the HGC. Hercules developed extensions, called ''HBASIC'', for IBM Advanced BASIC to add HGC support and Hercules cards came with ''Graph X'', a

software library In computer science, a library is a collection of non-volatile resources used by computer programs, often for software development. These may include configuration data, documentation, help data, message templates, pre-written code and subr ...

for Hercules graphical-mode support and

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s. Popular IBM PC programs such as

Lotus 1-2-3 Lotus 1-2-3 is a discontinued spreadsheet program from Lotus Software (later part of IBM). It was the first killer application of the IBM PC, was hugely popular in the 1980s, and significantly contributed to the success of IBM PC-compatibles i ...

spreadsheet,

AutoCAD AutoCAD is a commercial computer-aided design (CAD) and drafting software application. Developed and marketed by Autodesk, AutoCAD was first released in December 1982 as a desktop app running on microcomputers with internal graphics controllers. ...

computer-aided drafting,

Pagemaker Adobe PageMaker (formerly Aldus) is a discontinued desktop publishing computer program introduced in 1985 by the Aldus Corporation on the Apple Macintosh. The combination of the Macintosh's graphical user interface, PageMaker publishing software, ...

and Xerox Ventura desktop publishing, and

Microsoft Flight Simulator 2.0 ''Microsoft Flight Simulator'', commonly known as ''Microsoft Flight Simulator 2.0'' or ''FS2'', is a flight simulator video game. It was released in 1984 for the IBM PC as a self-booting disk. Publication history In May 1984, Microsoft releas ...

came with their own drivers to use the Hercules graphics mode. Though the graphics mode of the Hercules card is not CGA-compatible, it is similar enough to the two CGA graphics modes that with the use of third-party TSRs it can also work with programs written for the CGA card's standard graphics modes. As the Hercules card does not actually have color-generating circuitry, nor can it connect to a color monitor, color appears as simulated greyscale in varying dithering patterns.

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of the Hercules appeared, including generic models at very low prices, usually without the printer port. Hercules advertisements implied that use of generic Hercules clones can damage the monitor.

Reception

The Hercules Graphics Card was very successful, especially after Lotus 1-2-3 supported it, with one half million units sold by 1985. Hercules Computer Technology had 18% of the graphics card market, second to IBM. Hercules-compatible graphics cards shipped as standard hardware with most PC clones. As a

de facto standard A ''de facto'' standard is a custom or convention that has achieved a dominant position by public acceptance or market forces (for example, by early entrance to the market). is a Latin phrase (literally " in fact"), here meaning "in practice b ...

, support in software was widespread.

Later cards

The Hercules Graphics Card was followed by several other Hercules cards. ; Hercules Graphics Card Plus (HGC+): This card was released in June 1986 by

at an original retail price of $299. It was an enhancement of the HGC, adding support for redefinable fonts called RAMFONT in

compatible text mode. It was based around a specialty chip designed by

, unlike the original Hercules Graphics Card which used standard components. Software support included

v2,

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1.1, Framework II and

Microsoft Word Microsoft Word is a word processing software developed by Microsoft. It was first released on October 25, 1983, under the name ''Multi-Tool Word'' for Xenix systems. Subsequent versions were later written for several other platforms includin ...

3. ; Hercules Network Card Plus: In 1988 Hercules released the Network Card Plus, a variant of the Graphics Card Plus with an integrated

TOPS Total Operations Processing System (TOPS) is a computer system for managing railway locomotives and rolling stock, known for many years of use in the United Kingdom. TOPS was originally developed between the Southern Pacific Railroad (SP), S ...

/FlashTalk-compatible network adapter. Like the HGC+ it supported RAMFONT, but lacked a printer port. ; Hercules InColor Card: April 1987. Included color capabilities similar to the EGA, with 16 colors from a palette of 64. It retained the same two modes (80×25 text with redefinable fonts and 720×348 graphics), and was backward compatible with software written for the earlier monochrome Hercules cards. ; Hercules Color Card: Not to be confused with the InColor Card. A CGA-compatible video board. This board could coexist with the HGC and still allow both graphics pages to be used. It would detect when the second graphics page was selected and disable access to its own memory, which would otherwise have been at the same addresses.

Clone boards

Other boards offered Hercules compatibility. * SiS 86C12, 86C22 *

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Small Wonder Graphics Solution, 18700, Graphics Solution Plus * Tamarack Microelectronics TD3088A, TD3088A2, TD3088A3, TD3010, RY-3301, TD3010 *

Yamaha Yamaha may refer to: * Yamaha Corporation, a Japanese company with a wide range of products and services, established in 1887. The company is the largest shareholder of Yamaha Motor Company (below). ** Yamaha Music Foundation, an organization estab ...

V6366C-F, V6363-F, V6363 *

Winbond Winbond Electronics Corporation () is a Taiwan-based corporation founded in 1987. It produces semiconductors and several types of integrated circuits, most notably Dynamic RAM, Static RAM, Serial flash, microcontrollers, and personal computer ...

W86855AF, W86855AF *

NEC is a Japanese multinational corporation, multinational information technology and electronics corporation, headquartered in Minato, Tokyo. The company was known as the Nippon Electric Company, Limited, before rebranding in 1983 as NEC. It prov ...

μPD65042GD *

Tseng Labs Tseng Laboratories, Inc. (also known as Tseng Labs or TLI) was a maker of graphics chips and controllers for IBM PC compatibles, based in Newtown, Pennsylvania, and founded by Jack Hsiao Nan Tseng. Founded in 1983, Tseng Labs' first product ...

ET1000-A * DFI MG-150 *

Hitachi () is a Japanese multinational corporation, multinational Conglomerate (company), conglomerate corporation headquartered in Chiyoda, Tokyo, Japan. It is the parent company of the Hitachi Group (''Hitachi Gurūpu'') and had formed part of the Ni ...

HD6445P4, HD6845SP * RAM MCG2502, MCG2502 * Proton PT6121T * Acer M3127 *

Sigma Designs Sigma Designs was an American public corporation that designed and built high-performance system-on-a-chip semiconductor technologies for Internet-based set-top boxes, DVD players/recorders, high-definition televisions, media processors, digital ...

53C101+53C280A * CM607P Certain later models of the

Tandy 1000 The Tandy 1000 is the first in a line of IBM PC workalike home computer systems produced by the Tandy Corporation for sale in its Radio Shack and Radio Shack Computer Center chains of stores. Overview In December 1983, an executive with Tandy C ...

(such as the 1000 TL and SL) and the

Epson Equity The Epson Equity series of IBM Compatible Personal Computers was manufactured from 1985 until the early '90s by Epson Inc. Epson was well known for its dot matrix printers at the time and the Equity series represents their entry into the growing P ...

contained circuitry built into their CPU boards that supported Hercules display modes in addition to their standard CGA modes. File:ET1000-A.JPG, Tseng ET-1000 Hercules compatible board File:ATI Hercules Card 1986 (cropped and transparent).png,

Hercules compatible card from 1986 File:HGCclone.jpg, A Tamarack Microelectronics HGC-compatible card File:Uncle-RAY.jpg, Uncle-RAY Hercules compatible graphics card

History

Hardware design

Capabilities

Use

Reception

Later cards

Clone boards

See also

References

Further reading