Some panels advertise a resolution only slightly smaller than the native, such as 1360×765. Many Wide XGA panels do not advertise their native resolution in the standard timing descriptors, instead offering only a resolution of 1280×768.
Specifying 1368 pixels as the screen width would yield an unnatural screen height of 769.5 pixels. For 1366×768 pixel Wide XGA panels the nearest resolution expressible in the EDID standard timing descriptor syntax is 1360×765 pixels, typically leading to 3 pixel thin black bars. To be fully expressible, the size of wide screen display must thus be a multiple of 16×9 pixels. The number of vertical pixels is calculated from the horizontal resolution and the selected aspect ratio. This means that many graphics cards cannot express the native resolutions of the most common wide screen flat panel displays and liquid crystal display televisions.
#Switchresx drivers
Even in cases where the DTDs were read, the drivers are/were still often limited by the standard timing descriptor limitation that the horizontal/vertical resolutions must be evenly divisible by 8. Some graphics card drivers have historically coped poorly with the EDID, using only its standard timing descriptors rather than its Detailed Timing Descriptors (DTDs).
#Switchresx mac os x
Mac OS X natively reads EDID information and programs such as SwitchResX or Displa圜onfigX can display the information as well as use it to define custom resolutions.Į-EDID was introduced at the same time as E-DDC, which supports multiple extensions blocks and deprecated EDID version 2.0 structure (it can be incorporated in E-EDID as an optional extension block).
#Switchresx software
Many software packages can read and display the EDID information, such as read-edid for Linux and DOS, PowerStrip for Microsoft Windows and the X.Org Server for Linux and BSD unix.
#Switchresx Pc
The EDID PROM can often be read by the host PC even if the display itself is turned off.
#Switchresx serial
The EDID is often stored in the monitor in the firmware chip called serial EEPROM (electrically erasable programmable read-only memory) and is accessible via the I☬-bus at address 0x50. The channel for transmitting the EDID from the display to the graphics card is usually the I☬-bus, defined in DDC2B (DDC1 used a different serial format which never gained popularity). Some VGA connectors in personal computers provided a basic form of identification by connecting one, two or three pins to ground, but this coding was not standardized. īefore Display Data Channel (DDC) and EDID were defined, there was no standard way for a graphics card to know what kind of display device it was connected to. Version 2.0 defined a new 256-byte structure but it has been deprecated and replaced by E-EDID which supports multiple extension blocks.