NCR 7454, User Manual, Page: 202 / 244

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.