VGA (RGBHV)

VGA (Video Graphics Array) refers both to the IBM display standard introduced in 1987 and, more commonly in modern usage, to the analog RGBHV video signal carried over the DE-15 (HD-15) connector that became the universal standard for connecting computers to CRT monitors. On the EveryCRT wiki, "VGA (RGBHV)" designates this analog signal format and its associated connector, as distinct from the original IBM VGA graphics hardware specification.

History

IBM introduced the Video Graphics Array with the PS/2 line of personal computers in April 1987. VGA replaced the earlier CGA, EGA, and Hercules graphics standards and introduced the now-ubiquitous DE-15 connector (a high-density 15-pin D-subminiature connector with three rows of pins) as the standard computer video output. Previous IBM graphics adapters had used a 9-pin DE-9 connector; the larger DE-15 accommodated the additional signals needed for analog RGB output with separate sync, DDC data, and monitor identification.

The original VGA specification defined a maximum resolution of 640×480 at 60 Hz with 256 colors (from a palette of 262,144). However, the analog nature of the interface meant it imposed no hard resolution limit — the actual maximum resolution was determined by the capabilities of the graphics card and monitor, not the connector. Third-party "Super VGA" (SVGA) extensions rapidly pushed resolutions to 800×600, 1024×768, 1280×1024, and beyond, all using the same DE-15 connector and RGBHV signaling.

The DE-15 VGA connector remained the dominant PC display interface for nearly two decades, from 1987 through the mid-2000s, when digital interfaces (DVI-D, HDMI, DisplayPort) began to displace it. VGA outputs continued to appear on graphics cards and laptops into the mid-2010s, and many CRT monitors remain the primary use case for VGA connections today among retro computing and gaming enthusiasts.

Signal Characteristics

The VGA interface carries analog RGBHV signals: three color channels (red, green, blue) at 0.7V peak-to-peak into 75Ω, plus TTL-level horizontal and vertical sync pulses on separate pins.

Parameter	Value
Signal type	Analog RGBHV (five-channel)
R/G/B signal level	0.7V peak-to-peak, 75Ω impedance
H-sync / V-sync	TTL level (0–5V), active low (typically)
Connector	DE-15 (HD-15, 15-pin high-density D-sub)
Bandwidth	Up to ~400 MHz pixel clock (connector/cable limited)
Supported resolutions	320×200 through 2048×1536+ (hardware dependent)
DDC support	VESA Display Data Channel (DDC1/DDC2B) via pins 12/15

The DE-15 connector pinout:

Pin	Signal	Pin	Signal	Pin	Signal
1	Red video	6	Red ground	11	Monitor ID / DDC data
2	Green video	7	Green ground	12	DDC data (SDA) / ID
3	Blue video	8	Blue ground	13	H-sync
4	Monitor ID / Reserved	9	+5V (DDC power)	14	V-sync
5	Ground	10	Sync ground	15	DDC clock (SCL) / ID

Unlike the five-BNC professional connection (where each signal has its own fully shielded coaxial cable), the DE-15 connector carries all signals through a single multi-pin housing. The R, G, and B lines typically have individual mini-coax shielding within the cable, but share close proximity within the connector itself, which can introduce crosstalk at very high pixel clock rates. For this reason, professional applications often use five separate BNC connectors for the same RGBHV signals.

Use on CRT Displays

Computer CRT Monitors

The VGA DE-15 connector was the standard video input on virtually every PC CRT monitor manufactured from the late 1980s through the mid-2000s. These monitors ranged from basic fixed-frequency models (supporting only 640×480 at specific refresh rates) to advanced multi-sync displays supporting a wide range of resolutions and refresh rates.

Common horizontal scan rate ranges for computer CRT monitors include:

• Budget monitors — 31–50 kHz (640×480 to ~1024×768)
• Mid-range monitors — 31–70 kHz (up to 1280×1024)
• High-end monitors — 31–96+ kHz (up to 1600×1200 and beyond)
• Professional multi-sync — 15–100+ kHz (including 15 kHz for standard-definition video)

For retro gaming, multi-sync computer CRT monitors that support 15 kHz horizontal scan rates are particularly valuable, as they can display 240p and 480i signals from classic game consoles via RGBHV-to-RGBS conversion or direct connection with a sync combiner.

HD CRT Televisions

Some HD CRT televisions included a DE-15 VGA input for use as a computer display. This was more common on models sold in European and Asian markets, notably Sony's Super Fine Pitch (SFP) widescreen CRT televisions, which featured VGA inputs alongside standard AV connections. These inputs accepted RGBHV at 480p, 720p, 1080i, and sometimes native PC resolutions, though typically without HDCP support.

Professional Monitors

High-end professional CRT monitors (Sony BVM-D series, Barco reference monitors, Ikegami broadcast monitors) accept RGBHV via five BNC connectors rather than a DE-15 jack. Some models include both BNC and DE-15 inputs. The BNC connection provides superior signal integrity for demanding color-critical applications.

VGA and Retro Gaming

VGA connections are significant for the retro gaming community in several ways:

• Dreamcast VGA — the Sega Dreamcast was the first major game console to output a 480p VGA signal, via its proprietary VGA box or third-party cables. This makes the Dreamcast especially well-suited to VGA CRT monitors.
• PC retro gaming — using CRT Emudriver or similar software, modern PCs can output 15 kHz signals through their VGA ports for authentic retro display on standard-definition CRT monitors or televisions (with appropriate sync conversion).
• VGA-to-SCART — with a sync combiner, RGBHV can be converted to RGBS for use on European SCART-equipped CRT televisions, allowing a PC to drive a 15 kHz consumer CRT.
• VGA-to-BNC — simple passive breakout cables convert the DE-15 connector to five BNC connectors for use with professional monitors.

See Also

• RGBHV — The five-wire analog signal format carried by VGA
• RGBS — Four-wire RGB with composite sync
• RGsB — Three-wire RGB with sync on green
• DVI-D — Digital interface that replaced VGA for computer displays
• BNC — Professional connector for individual RGBHV channels