1TN3270(1) 386BSD Reference Manual TN3270(1) 2 3NNAAMMEE 4 ttnn33227700 - full-screen remote login to IBM VM/CMS 5 6SSYYNNOOPPSSIISS 7 ttnn33227700 [--dd] [--nn _f_i_l_e_n_a_m_e] [--tt _c_o_m_m_a_n_d_n_a_m_e] [_s_y_s_n_a_m_e [port]] 8 9DDEESSCCRRIIPPTTIIOONN 10 TTnn33227700 permits a full-screen, full-duplex connection from a UNIX machine 11 to an IBM (or compatible) machine. TTnn33227700 gives the appearance of being 12 logged in to the remote machine from an IBM 3270 terminal. Of course, 13 you must have an account on the machine to which you connect in order to 14 log in. TTnn33227700 looks to the user in many respects like the Yale ASCII 15 Terminal Communication System II. TTnn33227700 is actually a modification of 16 the Arpanet TELNET user interface (see telnet(1)) which will, in certain 17 circumstances, interpret and generate raw 3270 control streams. 18 19 The flags to ttnn33227700 are as follows: 20 21 --dd Turn on socket-level tracing (for super-user only) --nn_f_i_l_e_n_a_m_e 22 Specify a file to receive network trace data output (from 23 commands "toggle netdata" and "toggle options", see 24 telnet(1)); the default is for output to be directed to the 25 standard error file. --tt_c_o_m_m_a_n_d_n_a_m_e Specify a UNIX command to 26 process IBM 4994 style transparent mode data received from 27 the remote IBM machine. 28 29 _s_y_s_n_a_m_e The name of the remote system. If the remote name is NOT 30 specified, the user will be prompted for a command (see be- 31 low). 32 33 _p_o_r_t The port to connect to on the remote system. Normally, 34 ttnn33227700 attempts to connect to the standard TELNET port (port 35 23) on the remote machine. 36 37 When ttnn33227700 first connects to the remote system, it will negotiate to go 38 into 3270 mode. Part of this negotiation involves telling the remote 39 system what model 3270 it is emulating. In all cases, ttnn33227700 emulates a 40 3278 terminal. To decide which specific model, ttnn33227700 looks at the num- 41 ber of lines and columns on the actual terminal (as defined in the TERM 42 environment variable; see termcap(5)). The terminal (or window in which 43 ttnn33227700 is running, on multiple window systems) must have at least 80 44 columns and 24 lines, or ttnn33227700 will not go into emulation mode. If the 45 terminal does have at least 80 columns and at least 24 lines, the follow- 46 ing table describes the emulation: 47 48 minimum_size emulated 49 (rows*columns) terminal 50 -------------- ------------ 51 27*132 3278 model 5 52 43*80 3278 model 4 53 32*80 3278 model 3 54 24*80 3278 model 2. 55 56 Emulation of the 3270 terminal is done in the UNIX process. This emula- 57 tion involves mapping 3270-style commands from the host into appropriate 58 sequences to control the user's terminal screen. TTnn33227700 uses curses(3) 59 and the /_u_s_r/_s_h_a_r_e/_m_i_s_c/_t_e_r_m_c_a_p file to do this. The emulation also in- 60 volves simulating the special 3270 keyboard keys (program function keys, 61 etc.) by mapping sequences of keystrokes from the ASCII keyboard into 62 appropriate 3270 control strings. This mapping is terminal dependent and 63 is specified in a description file, /_u_s_r/_s_h_a_r_e/_m_i_s_c/_m_a_p_3_2_7_0, (see 64 map3270(5)) or in an environment variable MAP3270 (and, if necessary, 65 MAP3270A, MAP3270B, and so on - see mset(1)). Any special function keys 66 on the ASCII keyboard are used whenever possible. If an entry for the 67 user's terminal is not found, ttnn33227700 looks for an entry for the terminal 68 type _u_n_k_n_o_w_n. If this is not found, ttnn33227700 uses a default keyboard map- 69 ping (see map3270(5)). 70 71 The first character of each special keyboard mapping sequence is either 72 an ASCII escape (ESC), a control character, or an ASCII delete (DEL). If 73 the user types an unrecognized function key sequence, ttnn33227700 sends an 74 ASCII bell (BEL), or a visual bell if defined in the user's termcap en- 75 try, to the user's terminal and nothing is sent to the IBM host. 76 77 If ttnn33227700 is invoked without specifying a remote host system name, it en- 78 ters local command mode, indicated by the prompt ``tn3270> ''. In this 79 mode, ttnn33227700 accepts and executes all the commands of telnet(1), plus 80 one additional command: 81 82 ttrraannssccoomm Specify UNIX command for IBM 4994 style transparent mode 83 processing. 84 85 TTnn33227700 command mode may also be entered, after connecting to a host, by 86 typing a special escape sequence. If ttnn33227700 has succeeded in negotiating 87 3270 mode with the remote host, the escape sequence will be as defined by 88 the map3270 (see map3270(5)) entry for the user's terminal type (typi- 89 cally control-C); otherwise the escape sequence will initially be set to 90 the single character `^]' (control right square bracket). 91 92 While in command mode, any host login session is still alive but tem- 93 porarily suspended. The host login session may be resumed by entering an 94 empty line (press the RETURN key) in response to the command prompt. A 95 session may be terminated by logging off the foreign host, or by typing 96 ``quit'' or ``close'' while in local command mode. 97 98FFIILLEESS 99 /usr/share/misc/termcap 100 /usr/share/misc/map3270 101 102NNOOTTEESS 103 The IBM 4994 style transparent mode command is invoked when ttnn33227700 re- 104 ceives IBM 4994 style transparent output from the remote host. Output 105 and input pipes are created for communication between the two processes. 106 The pipes are closed when a 3270 clear command is received from the re- 107 mote hosts, signalling the end of transparent mode output. Transparent 108 mode is necessary for sending ASCII control characters over the 3270 ter- 109 minal connection; ASCII graphics terminal support is accomplished this 110 way. Developers of ttrraannssccoomm commands should note that the ttrraannssccoomm stdin 111 pipe end will be in CBREAK mode, with ECHO and CRMOD turned off. 112 113EENNVVIIRROONNMMEENNTT 114 TTnn33227700 checks the following environment variables: TERM, MAP3270, 115 MAP3270[A...]. Information on these can be found in mset(1). TTnn33227700 also 116 checks SHELL, KEYBD and API3270. 117 118SSEEEE AALLSSOO 119 mset(1), telnet(1), curses(3), termcap(3), termcap(5), map3270(5), 120 121 "Yale ASCII Terminal Communication", _S_y_s_t_e_m _I_I _P_r_o_g_r_a_m 122 _D_e_s_c_r_i_p_t_i_o_n/_O_p_e_r_a_t_o_r'_s _M_a_n_u_a_l, IBM SB30-1911. 123 124HHIISSTTOORRYY 125 The ttnn33227700 command appeared in 4.3BSD. 126 127BBUUGGSS 128 Tn3270 is slow and uses system resources prodigiously. 129 130 Not all 3270 functions are supported, nor all Yale enhancements. 131 132 133 Error conditions (attempting to enter data in a protected field, for ex- 134 ample) should cause a message to be sent to the user's terminal instead 135 of just ringing a bell. 136 1374.3 Berkeley Distribution July 27, 1991 4 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199