NCR 7454 Hardware User's Manual page 156

6-8 Chapter 6: NCR 7454 4x20 Customer Display
Format:
Description:
Format:
Description:
Format:
Description:
Reset Display
1B 01
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
1B 02
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
1B 03
This in now an invalid command.