Facts Vesa DDC

Almost all PC monitors and flat displays contain an “Enhanced Extended Monitor Identifaction” (E-EDID) EEPROM, which contains informations about the features of the unit. E.g. it contains informations about the supported video modes. This EEPROM is interfaced via the SMBus.

The BIOS and the operating system of the PC read this information via DDC (Display Data Channel) from the monitor. So this information gets transfered over the VGA or DVI cable to the PC.

E-EDID Standard

The first version of EDID (1.0) has been released the VESA organisation (http://www.vesa.org), in 1994. Two years later it has been replaced by version 1.1. The current version, which has been released in 2000, is 1.3.

The standard describes the content of the 128 bytes in the EEPROM.

Access E-EDID Data

Tracii XL 2.0 supports manufacturer of monitors and TFT displays by the following features:

  • read and write E-EDID images via Tracii XL/Tracii XL 2.0
  • import and export E-EDID images
  • dialog for creating and interpreting E-EDID images


To use the VESA E-EDID support you want a Tracer option for your Tracii XL/Tracii XL 2.0. For the outdated VGA we additionally can a special VGA cable to access the monitor’s SMbus.