My SCO Unix X or Linux or character screen is completely unreadable and I cannot type commands exit or switch to another virtual console screen.

It is possible for you to get stuck in a really bad GUI, stuck so badly that CTRL-ALT and F1 will not switch you to a text screen. However, appearances can be deceiving: it's usually the case that it has switched you, but the screen is just confused by the incorrect graphics configuration. To fix this requires logging in "blind":

Hold CTRL and ALT, and press F1 (or any other function key if F1 is where you started). Release those keys, and press CTRL-U and then CTRL-J. Login, taking it on faith that the "Password" prompt displayed even though you can't see it. It wouldn't hurt to count to three after typing "root" just to give it time to come up. Press enter a few times, and then carefully type

 /etc/clean_screen
 

If that doesn't work, try

 /etc/clean_screen -g 
 

And if they still don't work, do Control-J's instead of ENTERS before you type and after.

If you were already logged in on tty01, then just a couple of Enters followed by "/etc/clean_screen" should do it.

Linux has a similar command, but it requires some forethought on your part: you need to have run "savetextmode" BEFORE you have a problem. Therefore, the obvious thing to do is to put it in one of the startup scripts. Then, if you need it, you'd run "textmode" (again, surrounded by CTRL-J's) to restore your screen.

Without forethought, you can try a simple "reset" or "echo ^V^O" (control V control O).

Also see fixing garbled display.

These methods also work when you've garbled the screen by cat'ing a binary file or have crashed out of an app unexpectedly.

For that last (crashing out of an app) "stty sane" or "reset" (surrounded by Control-J's) is probably all you need on any Unix.

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More Articles by Tony Lawrence © 2013-07-18 Tony Lawrence