1 01/11/82 Modes Operation
2
3 The following list of modes are recognized by the tty_ I/O module,
4 set_tty command and the modes preaccess request. The modes operation
5 to tty_ is supported when the I/O switch is open.
6
7 Some modes have a complement indicated by the circumflex character
8 ^ that turns the mode off e.g. ^erkl. For these modes the
9 complement is displayed with the mode. Normal defaults are indicated
10 for those modes that are generally independent of terminal type. The
11 modes string is processed from left to right. Thus, if two or more
12 contradictory modes appear within the same modes string, the rightmost
13 mode prevails.
14
15
16 List of modes:
17 8bit, ^8bit
18 causes input characters to be received without removing the 8th
19 high-order bit, which is normally interpreted as a parity bit.
20 This mode is valid for HSLA channels only. Default is off.
21 blk_xfer, ^blk_xfer
22 specifies that the user's terminal is capable of transmitting a
23 block or "frame" of input all at once in response to a single
24 keystroke. The system may not handle such input correctly unless
25 blk_xfer mode is on and the set_framing_chars order has seen issued.
26 Default is off.
27 breakall, ^breakall
28 enables a mode in which all characters are assumed to be break
29 characters, making each character available to the user process as
30 soon as it is typed. This mode only affects get_chars operations.
31 Default is off.
32
33
34 can, ^can
35 performs standard canonicalization on input. Default is on.
36 can_type=overstrike, can_type=replace
37 specifies the method to be used to convert an input string to
38 canonical form. Canonicalization is only performed when the I/O
39 switch is in "can" mode. Default is can_type=overstrike.
40 capo, ^capo
41 outputs all lowercase letters in uppercase. If edited mode is on,
42 uppercase letters are printed normally; if edited mode is off and
43 capo mode is on, uppercase letters are preceded by an escape \
44 character. Default is off.
45 crecho, ^crecho
46 echoes a carriage return when a line feed is typed. This mode can
47 only be used with terminals and line types capable of receiving and
48 transmitting simultaneously.
49
50
51 ctl_char, ^ctl_char
52 specifies that ASCII control characters that do not cause carriage
53 or paper motion are to be accepted as input, except for the NUL
54 character. If the mode is off, all such characters are discarded.
55 Default is off.
56 default
57 is a shorthand way of specifying erkl, can, ^rawi, ^rawo, ^wake_tbl,
58 and esc. The settings for other modes are not affected.
59 echoplex, ^echoplex
60 echoes all characters typed on the terminal. The same restriction
61 applies as for crecho; it must also be possible to disable the
62 terminal's local copy function.
63
64
65 edited, ^edited
66 suppresses printing of characters for which there is no defined
67 Multics equivalent on the device referenced. If edited mode is off,
68 the 9-bit octal representation of the character is printed.
69 Default is off.
70 erkl, ^erkl
71 performs "erase" and "kill" processing on input. Default is on.
72 esc, ^esc
73 enables escape processing on all input read from the device.
74 Default is on.
75 force
76 specifies that if the modes string contains unrecognized or invalid
77 modes, they are to be ignored and any valid modes are to be set. If
78 force is not specified, invalid modes cause an error code to be
79 returned, and no modes are set.
80
81
82 fulldpx, ^fulldpx
83 allows the terminal to receive and transmit simultaneously. This
84 mode should be explicitly enabled before enabling echoplex mode.
85 hndlquit, ^hndlquit
86 echoes a newline character and performs a resetread of the
87 associated stream when a quit signal is detected. Default is on.
88 iflow, ^iflow
89 specifies that input flow control characters are to be recognized
90 and/or sent to the terminal. The characters must be set before
91 iflow mode can be turned on.
92 init
93 sets all switch type modes off, sets line length to 50, and sets
94 page length to zero.
95
96
97 lfecho, ^lfecho
98 echoes and inserts a line feed in the user's input stream when a
99 carriage return is typed. The same restriction applies as for
100 crecho.
101 llN, ^ll
102 specifies the length in character positions of a terminal line. If
103 an attempt is made to output a line longer than this length, the
104 excess characters are placed on the next line. If ^ll is specified,
105 line length checking is disabled. In this case, if a line of more
106 than 255 column positions is output by a single call to
107 iox_$put_chars, some extra white space may appear on the terminal.
108
109
110 no_outp, ^no_outp
111 causes output characters to be sent to the terminal without the
112 addition of parity bits. If this mode and rawo mode are on, any
113 8-bit pattern can be sent to the terminal. This mode is valid for
114 HSLA channels only. Default is off.
115 oddp, ^oddp
116 causes any parity generation that is done to the channel to assume
117 odd parity. Otherwise, even parity is assumed for line types other
118 than 2741 and 1050. This mode is valid for HSLA channels only.
119 Default is off.
120 oflow, ^oflow
121 specifies that output flow control characters are to be recognized
122 when sent by the terminal. The characters and the protocol to be
123 used must be set before oflow mode can be turned on.
124
125
126 plN, ^pl
127 specifies the length in lines of a page. When an attempt is made
128 to exceed this length, a warning message is printed. When the
129 user types a formfeed or newline character any break character,
130 the output continues with the next page. the warning message is
131 normally the string "EOP", but can be changed by means of the
132 set_special control order. The string is displayed on a new line
133 after N consecutive output lines are sent to the screen including
134 long lines which are folded as more than one output line. To have
135 the end-of-page string displayed on the screen without scrolling
136 lines off the top, N should be set to one less than the page length
137 capability of the screen, unless the end-of-page string is a null
138 string. In this case, output stops at the end of the last line of
139 the page or screen. If ^pl is specified, end-of-page checking is
140 disabled. See description of scroll mode below.
141 polite, ^polite
142 does not print output sent to the terminal while the user is typing
143 input until the carriage is at the left margin, unless the user
144 allows 30 seconds to pass without typing a newline. Default is
145 off.
146
147
148 prefixnl, ^prefixnl
149 controls what happens when terminal output interrupts a partially
150 complete input line. In prefixnl mode, a newline character is
151 inserted in order to start the output at the left margin; in
152 ^prefixnl mode, the output starts in the current column position.
153 Default is on. Polite mode controls when input may be interrupted
154 by output; prefixnl controls what happens when such an interruption
155 occurs.
156 rawi, ^rawi
157 reads the data specified from the device directly without any
158 conversion or processing. Default is off.
159 rawo, ^rawo
160 writes data to the device directly without any conversion or
161 processing. Default is off.
162
163
164 red, ^red
165 sends red and black shifts to the terminal.
166 replay, ^replay
167 prints any partial input line that is interrupted by output at the
168 conclusion of the output, and leaves the carriage in the same
169 position as when the interruption occurred. Default is off.
170 scroll, ^scroll
171 specifies that end-of-page checking is performed in a manner suited
172 to scrolling video terminals. If the mode is on, the end-of-page
173 condition occurs only when a full page of output is displayed
174 without intervening input lines. The mode is ignored whenever
175 end-of-page checking is disabled. Default is off.
176 tabecho, ^tabecho
177 echoes the appropriate number of spaces when a horizontal tab is
178 typed. The same restriction applies as for crecho.
179
180
181 tabs, ^tabs
182 inserts tabs in output in place of spaces when appropriate. If tabs
183 mode is off, all tab characters are mapped into the appropriate
184 number of spaces.
185 vertsp, ^vertsp
186 performs the vertical tab and formfeed functions, and sends
187 appropriate characters to the device. Otherwise, such characters
188 are escaped. Default is off.
189 wake_tbl, ^wake_tbl
190 causes input wakeups to occur only when specified wakeup characters
191 are received. Wakeup characters are defined by the set_wakeup_table
192 order. This mode is ineffective unless breakall mode is also on.
193 This mode cannot be set unless a wakeup table has been previously
194 defined.