CRM—Show Control Character Mode

Enable or disable control characters to be displayed.

Default: Interpret

Format

CSI 9/11	3 3/3	h 6/8	Set: show control character.
CSI 9/11	3 3/3	l 6/12	Reset: interpret control character.

Description

When CRM mode is set, all characters (graphic or control) are displayed in the CRM font. All control functions are displayed as graphic characters. No control functions are executed, except LF, FF, and VT, which are represented in the CRM font before a CRLF (new line) is executed. XOFF (DC3) and XON (DC1) are used for flow control (if enabled). DC1 and DC3 are displayed after execution.

This function affects data received in the data stream following the change to CRM mode. Characters already displayed are not affected. Entering Control Representation mode temporarily causes G0 and GL to be loaded with ASCII. G2 and GR are loaded with user-selected Supplemental Graphic characters if in 8-bit Multinational Character mode.

Notes on CRM

• CRM mode works in all VT terminal modes.
• NUL is displayed and is not useful as a fill character.
• CRM mode overrides Printer Controller mode. When in CRM, Printer Controller mode is temporarily off.
• In local mode and CRM (or local echo and CRM), CSI sequences may be represented as either ESC Fe sequences (such as ESC [) or as C1 controls. Conversely, C1 controls may be represented as either C1 controls or as ESC Fe sequences.
• In CRM mode, auto-wrap always occurs at the right margin. Sending a sequence or disabling auto-wrap in Set-Up is ignored.
• Terminal Device Protocol commands are not affected if Control Representation mode is entered.