6530 Programmer's Guide

Overview
6530 Programmer’s Guide 1-13
The host sends the terminal a mode switch message of the form:
SOH mode ETX LRC
where:
SOH, ETX, and LRC are communications control characters. SOH
acts as a start of header for the message. ETX indicates the end of
text for the message. LRC is a longitudinal redundancy check
character used to detect errors in the transmission.
mode is either C for conversational or B for block, to specify the
new mode of operation.
When the 6530 changes modes, it performs one of the following
initialization sequences:
Switch from conversational to block mode
Locks the keyboard.
Sets the submode to nonprotect.
Sets the maximum number of pages to the default or the last setting
of the set max page number (Esc p) escape sequence. See “Set Max
Page Number (Esc p)” on page 3-12.
Clears all pages to spaces except page 1, which retains the text that
was displayed on the screen in conversational mode.
Sets the display page and the select page to page 1.
Sets the cursor address and buffer address for all pages to row 1,
column 1 (home position).
Clears all horizontal tab stops.
Enables local line editing.
Sets insert mode to off.
Sets the video prior condition register to normal video.
Sets the data type table to its default values. (See Appendix D.)
Clears the message area in the message/status line and displays
BLOCK in the status area.