6530 Programmer's Guide

Conversational Mode Operation
6530 Programmer’s Guide 2-53
Keyboard
Operations
In conversational mode, some keys (or key combinations) generate ASCII
character codes. The 6530 transmits these ASCII codes to the host after
each character is typed. In half-duplex, the 6530 acts upon these character
codes (performs the operation specified by the code) as it transmits them
to the host. In full-duplex, the 6530 only transmits the character codes and
does not act upon them until they are echoed back by the host.
For example, when the user presses an alphanumeric key, the 6530 sends
the ASCII code for that character to the host. In half-duplex, the 6530 also
displays the character on the screen and moves the cursor to the next
position. In full-duplex, the character is not displayed and the cursor is
not moved until the character is returned from the host.
Table 2-8 lists the keys that generate ASCII character codes and describes
the actions performed when the 6530 processes the character.
Table 2-8. Keys That Generate ASCII Codes
Key(s) Description
Displayable
alphanumeric and
special characters
Transmits the ASCII code for the character, at the
current cursor location, and increments the cursor
location by one position.
Ctrl-
key Transmits the ASCII control code associated with key
and performs the function for that control code. For
example, the Ctrl-G keys generate the BEL control
character (0H). See Appendix A for the list of keys used
to generate control characters from the keyboard.
Unrecognized control codes are transmitted to the host
but otherwise ignored. The recognized control codes
are described throughout this chapter.
Esc Transmits an Esc control character (1BH) and
interprets subsequent characters as an escape
sequence. Unrecognized escape sequences cause a
command error to occur. The recognized sequences
are described throughout this chapter.
Fl through F10 and
either Alt-Fl
through Alt-F6 or
Alt-F3 through
Alt-F6 (unshifted or
shifted)
Note: Transmit function key messages are described in
“Function Keys” on page 2-51.