NCR NCR7454 manual Reset Display, Erase Display, Invalid Command

6-8 Chapter 6: NCR 7454 4x20 Customer Display

	Reset Display
Format:	1B 01
Description:	This command executes the power-down power-up diagnostic
	sequence. The BUSY line is set to active condition. The micro-controller
	test consists of a sum-check test on the ROM and a write/read test on
	the RAM. After executing the command, the display screen is cleared,
	the cursor moves to the 0 position, the BUSY line is set to inactive
	conditions, and all registers and variables are initialized. Note that the
	screen is cleared during this command. If a host needs previous data
	redisplayed, the host must resend the previous data after this
	command has completed.

	Erase Display
Format:	1B 02
Description:	This command clears all of the displayed characters by writing a space
	to each display position. A space is defined as character 0x20 of the
	current character set. The cursor moves to the 0 position.

	Invalid Command
Format:	1B 03
Description:	This in now an invalid command.