1 IBM 3270 Display System support
3 This file describes the driver that supports local channel attachment
4 of IBM 3270 devices. It consists of three sections:
12 This paper describes installing and operating 3270 devices under
13 Linux/390. A 3270 device is a block-mode rows-and-columns terminal of
14 which I'm sure hundreds of millions were sold by IBM and clonemakers
15 twenty and thirty years ago.
17 You may have 3270s in-house and not know it. If you're using the
18 VM-ESA operating system, define a 3270 to your virtual machine by using
19 the command "DEF GRAF <hex-address>" This paper presumes you will be
20 defining four 3270s with the CP/CMS commands
27 Your network connection from VM-ESA allows you to use x3270, tn3270, or
28 another 3270 emulator, started from an xterm window on your PC or
29 workstation. With the DEF GRAF command, an application such as xterm,
30 and this Linux-390 3270 driver, you have another way of talking to your
33 This paper covers installation of the driver and operation of a
39 You install the driver by installing a patch, doing a kernel build, and
40 running the configuration script (config3270.sh, in this directory).
42 WARNING: If you are using 3270 console support, you must rerun the
43 configuration script every time you change the console's address (perhaps
44 by using the condev= parameter in silo's /boot/parmfile). More precisely,
45 you should rerun the configuration script every time your set of 3270s,
46 including the console 3270, changes subchannel identifier relative to
47 one another. ReIPL as soon as possible after running the configuration
48 script and the resulting /tmp/mkdev3270.
50 If you have chosen to make tub3270 a module, you add a line to
51 /etc/modules.conf. If you are working on a VM virtual machine, you
52 can use DEF GRAF to define virtual 3270 devices.
54 You may generate both 3270 and 3215 console support, or one or the
55 other, or neither. If you generate both, the console type under VM is
56 not changed. Use #CP Q TERM to see what the current console type is.
57 Use #CP TERM CONMODE 3270 to change it to 3270. If you generate only
58 3270 console support, then the driver automatically converts your console
59 at boot time to a 3270 if it is a 3215.
61 In brief, these are the steps:
62 1. Install the tub3270 patch
63 2. (If a module) add a line to /etc/modules.conf
64 3. (If VM) define devices with DEF GRAF
68 To test that everything works, assuming VM and x3270,
69 1. Bring up an x3270 window.
70 2. Use the DIAL command in that window.
71 3. You should immediately see a Linux login screen.
73 Here are the installation steps in detail:
75 1. The 3270 driver is a part of the official Linux kernel
76 source. Build a tree with the kernel source and any necessary
79 (If you wish to disable 3215 console support, edit
80 .config; change CONFIG_TN3215's value to "n";
81 and rerun "make oldconfig".)
87 2. (Perform this step only if you have configured tub3270 as a
88 module.) Add a line to /etc/modules.conf to automatically
89 load the driver when it's needed. With this line added,
90 you will see login prompts appear on your 3270s as soon as
91 boot is complete (or with emulated 3270s, as soon as you dial
92 into your vm guest using the command "DIAL <vmguestname>").
93 Since the line-mode major number is 227, the line to add to
94 /etc/modules.conf should be:
95 alias char-major-227 tub3270
97 3. Define graphic devices to your vm guest machine, if you
98 haven't already. Define them before you reboot (reipl):
104 4. Reboot. The reboot process scans hardware devices, including
105 3270s, and this enables the tub3270 driver once loaded to respond
106 correctly to the configuration requests of the next step. If
107 you have chosen 3270 console support, your console now behaves
108 as a 3270, not a 3215.
110 5. Run the 3270 configuration script config3270. It is
111 distributed in this same directory, Documentation/s390, as
112 config3270.sh. Inspect the output script it produces,
113 /tmp/mkdev3270, and then run that script. This will create the
114 necessary character special device files and make the necessary
115 changes to /etc/inittab. If you have selected DEVFS, the driver
116 itself creates the device files, and /tmp/mkdev3270 only changes
119 Then notify /sbin/init that /etc/inittab has changed, by issuing
120 the telinit command with the q operand:
121 cd /usr/src/linux/Documentation/s390
126 This should be sufficient for your first time. If your 3270
127 configuration has changed and you're reusing config3270, you
128 should follow these steps:
129 Change 3270 configuration
131 Run config3270 and /tmp/mkdev3270
134 Here are the testing steps in detail:
136 1. Bring up an x3270 window, or use an actual hardware 3278 or
137 3279, or use the 3270 emulator of your choice. You would be
138 running the emulator on your PC or workstation. You would use
139 the command, for example,
140 x3270 vm-esa-domain-name &
141 if you wanted a 3278 Model 4 with 43 rows of 80 columns, the
142 default model number. The driver does not take advantage of
145 The screen you should now see contains a VM logo with input
146 lines near the bottom. Use TAB to move to the bottom line,
147 probably labeled "COMMAND ===>".
149 2. Use the DIAL command instead of the LOGIN command to connect
150 to one of the virtual 3270s you defined with the DEF GRAF
152 dial my-vm-guest-name
154 3. You should immediately see a login prompt from your
155 Linux-390 operating system. If that does not happen, you would
156 see instead the line "DIALED TO my-vm-guest-name 0620".
158 To troubleshoot: do these things.
160 A. Is the driver loaded? Use the lsmod command (no operands)
161 to find out. Probably it isn't. Try loading it manually, with
162 the command "insmod tub3270". Does that command give error
163 messages? Ha! There's your problem.
165 B. Is the /etc/inittab file modified as in installation step 3
166 above? Use the grep command to find out; for instance, issue
167 "grep 3270 /etc/inittab". Nothing found? There's your
170 C. Are the device special files created, as in installation
171 step 2 above? Use the ls -l command to find out; for instance,
172 issue "ls -l /dev/3270/tty620". The output should start with the
173 letter "c" meaning character device and should contain "227, 1"
174 just to the left of the device name. No such file? no "c"?
175 Wrong major number? Wrong minor number? There's your
178 D. Do you get the message
179 "HCPDIA047E my-vm-guest-name 0620 does not exist"?
180 If so, you must issue the command "DEF GRAF 620" from your VM
181 3215 console and then reboot the system.
187 The driver defines three areas on the 3270 screen: the log area, the
188 input area, and the status area.
190 The log area takes up all but the bottom two lines of the screen. The
191 driver writes terminal output to it, starting at the top line and going
192 down. When it fills, the status area changes from "Linux Running" to
193 "Linux More...". After a scrolling timeout of (default) 5 sec, the
194 screen clears and more output is written, from the top down.
196 The input area extends from the beginning of the second-to-last screen
197 line to the start of the status area. You type commands in this area
198 and hit ENTER to execute them.
200 The status area initializes to "Linux Running" to give you a warm
201 fuzzy feeling. When the log area fills up and output awaits, it
202 changes to "Linux More...". At this time you can do several things or
203 nothing. If you do nothing, the screen will clear in (default) 5 sec
204 and more output will appear. You may hit ENTER with nothing typed in
205 the input area to toggle between "Linux More..." and "Linux Holding",
206 which indicates no scrolling will occur. (If you hit ENTER with "Linux
207 Running" and nothing typed, the application receives a newline.)
209 You may change the scrolling timeout value. For example, the following
211 echo scrolltime=60 > /proc/tty/driver/tty3270
212 changes the scrolling timeout value to 60 sec. Set scrolltime to 0 if
213 you wish to prevent scrolling entirely.
215 Other things you may do when the log area fills up are: hit PA2 to
216 clear the log area and write more output to it, or hit CLEAR to clear
217 the log area and the input area and write more output to the log area.
219 Some of the Program Function (PF) and Program Attention (PA) keys are
220 preassigned special functions. The ones that are not yield an alarm
223 PA1 causes a SIGINT to the currently running application. You may do
224 the same thing from the input area, by typing "^C" and hitting ENTER.
226 PA2 causes the log area to be cleared. If output awaits, it is then
227 written to the log area.
229 PF3 causes an EOF to be received as input by the application. You may
230 cause an EOF also by typing "^D" and hitting ENTER.
232 No PF key is preassigned to cause a job suspension, but you may cause a
233 job suspension by typing "^Z" and hitting ENTER. You may wish to
234 assign this function to a PF key. To make PF7 cause job suspension,
236 echo pf7=^z > /proc/tty/driver/tty3270
238 If the input you type does not end with the two characters "^n", the
239 driver appends a newline character and sends it to the tty driver;
240 otherwise the driver strips the "^n" and does not append a newline.
241 The IBM 3215 driver behaves similarly.
243 Pf10 causes the most recent command to be retrieved from the tube's
244 command stack (default depth 20) and displayed in the input area. You
245 may hit PF10 again for the next-most-recent command, and so on. A
246 command is entered into the stack only when the input area is not made
247 invisible (such as for password entry) and it is not identical to the
248 current top entry. PF10 rotates backward through the command stack;
249 PF11 rotates forward. You may assign the backward function to any PF
250 key (or PA key, for that matter), say, PA3, with the command:
251 echo -e pa3=\\033k > /proc/tty/driver/tty3270
252 This assigns the string ESC-k to PA3. Similarly, the string ESC-j
253 performs the forward function. (Rationale: In bash with vi-mode line
254 editing, ESC-k and ESC-j retrieve backward and forward history.
255 Suggestions welcome.)
257 Is a stack size of twenty commands not to your liking? Change it on
258 the fly. To change to saving the last 100 commands, execute the
260 echo recallsize=100 > /proc/tty/driver/tty3270
262 Have a command you issue frequently? Assign it to a PF or PA key! Use
264 echo pf24="mkdir foobar; cd foobar" > /proc/tty/driver/tty3270
265 to execute the commands mkdir foobar and cd foobar immediately when you
266 hit PF24. Want to see the command line first, before you execute it?
267 Use the -n option of the echo command:
268 echo -n pf24="mkdir foo; cd foo" > /proc/tty/driver/tty3270
272 Happy testing! I welcome any and all comments about this document, the
275 Dick Hitt <rbh00@utsglobal.com>