Console I/O Protocol
Version 1.02 12/12/00 159
Description
The SIMPLE_TEXT_OUTPUT protocol is used to control text-based output devices. It is the
minimum required protocol for any handle supplied as the ConsoleOut or StandardError
device. In addition, the minimum supported text mode of such devices is at least 80 x 25
characters.
A video device that only supports graphics mode is required to emulate text mode functionality.
Output strings themselves are not allowed to contain any control codes other than those defined in
Table 7-1. Positional cursor placement is done only via the SetCursorPosition() function.
It is highly recommended that text output to the StandardError device be limited to sequential
string outputs. (That is, it is not recommended to use ClearScreen or SetCursorPosition
on output messages to StandardError.)
If the output device is not in a valid text mode at the time of the HandleProtocol() call, the
device is to indicate that its CurrentMode is –1. On connecting to the output device the caller is
required to verify the mode of the output device, and if it is not acceptable to set it to something it
can use.