Arclight-MCP-Bot: Create TTL RGB signal format page (via create-page on MediaWiki MCP Server)

2026-02-02T06:00:35Z

Create TTL RGB signal format page (via create-page on MediaWiki MCP Server)

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'''TTL RGB''' (also called '''Digital RGB''') is a video signal format that uses TTL (Transistor-Transistor Logic) voltage levels to represent color information. Unlike analog RGB which uses continuous voltage levels, TTL RGB uses discrete on/off states for each color channel.

== Overview ==

In TTL RGB, each color channel (Red, Green, Blue) is either fully on (+5V) or fully off (0V). This limits the number of displayable colors but simplifies the circuitry required.

== Color Depth ==

=== 8 Colors (3-bit RGB) ===

Basic TTL RGB with one bit per channel produces 2³ = 8 possible colors:

{| class="wikitable"
! R !! G !! B !! Color
|-
| 0 || 0 || 0 || Black
|-
| 0 || 0 || 1 || Blue
|-
| 0 || 1 || 0 || Green
|-
| 0 || 1 || 1 || Cyan
|-
| 1 || 0 || 0 || Red
|-
| 1 || 0 || 1 || Magenta
|-
| 1 || 1 || 0 || Yellow
|-
| 1 || 1 || 1 || White
|}

=== 16 Colors (RGBI) ===

Adding an Intensity bit doubles the palette to 16 colors. When the Intensity signal is active, all colors are displayed at higher brightness. This was used in CGA monitors and some Japanese computer displays.

== Signal Specifications ==

{| class="wikitable"
! Parameter !! Value
|-
| Logic high || +2.4V to +5V (TTL)
|-
| Logic low || 0V to +0.8V (TTL)
|-
| H-sync || Separate, TTL level, typically active low
|-
| V-sync || Separate, TTL level, typically active low
|-
| Impedance || TTL (not 75Ω terminated)
|}

== Comparison with Analog RGB ==

{| class="wikitable"
! Feature !! TTL RGB !! Analog RGB ([[RGBS]])
|-
| Signal levels || 0V / 5V (digital) || 0-0.7Vpp (continuous)
|-
| Colors || 8 or 16 || Thousands to millions
|-
| Impedance || TTL || 75Ω
|-
| Common connectors || [[EIAJ-8]], DE-9 || [[JP21]], [[SCART]], BNC
|-
| Typical use || 1980s computers || Professional monitors, consoles
|}

== Common Connectors ==

* [[EIAJ-8]] - Rectangular 8-pin connector (Japanese monitors)
* DE-9 - 9-pin D-sub (CGA monitors, some computers)
* [[8-pin DIN 45326]] - Round DIN (some computer outputs, though usually analog)

== Compatible Equipment ==

=== Monitors ===
* Sony Profeel Pro series ([[Sony KX-21HV1|KX-21HV1]], [[Sony KX-27HV1|KX-27HV1]])
* Sony KV-1311CR, KV-14CP1, KX-14HD1
* NEC PC-TV series
* Sharp CU series
* Various CGA-compatible monitors

=== Computers ===
* IBM PC with CGA card
* Fujitsu FM-X, FM-7
* Pioneer PX-7 (MSX with laserdisc)
* General PCT-55
* NEC PC-8800 series (some models)

== See Also ==

* [[RGBS]] - Analog RGB with composite sync
* [[RGBHV]] - Analog RGB with separate H/V sync
* [[EIAJ-8]] - Common TTL RGB connector
* [[Composite (CVBS)]] - Composite video signal

== References ==

* [https://www.msx.org/wiki/Digital_RGB_connector Digital RGB connector] - MSX Wiki

[[Category:Video signal formats]]

TTL RGB - Revision history

Arclight-MCP-Bot: Create TTL RGB signal format page (via create-page on MediaWiki MCP Server)