README file for Lock 2.0 6/17/91 CHANGES SINCE 1.0 o Fixed for NeXT Release 2.0. This accounts for most of the changes. o Simple screen-saver feature. When locked, the Lock window shifts around periodically to prevent burn-in of the window. The interval between moves is determined by the system's dim time, which can be set using Preferences. The window only moves around slightly so that it always appears to be centered. ABOUT LOCK Lock is an application which lets you lock your screen when you leave your NeXT computer unattended for a period of time. The program locks the console screen by freezing on-screen windows or by turning the display black. You can lock the screen either with your own password or with an access code that you set. In addition, Lock has a built-in fully-functional 15-puzzle. This document tells you how to use Lock. LOCKING THE SCREEN First, launch the Lock program and wait for the Lock window to appear. The lock can be set in two ways. The simpler method is to lock the screen using your own login password. After the program comes up, click the "Use password" button (or just hit the Return key). Alternatively, you can lock the screen by entering an "access code" by using the buttons of the 15-puzzle. (A simple on-screen keypad would have done nicely, but someone suggested that it would be more interesting to put a 15-puzzle in the program.) Each button in the puzzle represents a number that can be part of the access code. The button that you click on will become part of the sequence you reproduce when unlocking the screen. Each time you enter a number, the cursor in the access code field will advance by one position. For example, if you click on 2 and then the 15 button twice, the access code will be 2-15-15, not 2-1-5-1-5. You may enter up to a maximum of 16 numbers for the code. Don't worry about the fact that the puzzle pieces slide as the code is being entered; only the button you click on will be significant. Once you've entered the code, just hit the "Set code" button to lock the screen. When you lock your screen, Lock will freeze all on-screen windows. The Lock window remains on screen. No one will be able to tamper with your on-screen applications. No applications can be launched from the dock either. However, any computation in progress will still run, and any screen updates made by programs will be shown after you unlock. If you want more privacy, there is an additional feature which may be helpful; by holding down the Command key while clicking on the lock button, the screen will blacken instead of freezing. You may think of it as a simple screen dimmer. If, before locking your screen, you decide to cancel the entire operation, hit the "Cancel" button. This command will terminate the application. UNLOCKING THE SCREEN No matter how you locked your screen, you can unlock it by entering your login password or the root password. If you have previously locked the screen using an access code, you may also unlock it by reproducing the code using the buttons of the 15-puzzle. An incorrect entry will make the Lock window shake. This is like the behavior of the standard login window when someone gives incorrect login information. You will then again be asked for the correct entry. (Of course, you can always reboot the machine to unlock.) WORKING THE PUZZLE The 15-puzzle in Lock is a full-implementation of a 15-puzzle which can solve itself. The puzzle was incorporated into this program for purely recreational reasons. (NeXT machines shouldn't be completely useless when the screen is locked.) This puzzle is similar in operation to the Puzzle Desk Accessory on the Macintosh and the xpuzzle program in X windows. You may perform three functions on the puzzle: reset it, scramble it or tell it to solve itself. These three functions are accessed via the Puzzle pull-down menu in the Lock window. Choosing Reset from this menu will set the puzzle to its unscrambled state. Scramble will randomly move the pieces around several times, and Solve moves the pieces around in order to solve the puzzle. THE POWER KEY The Power key is still functional when the screen is locked. Because screen updates are not allowed, the Power Off panel does not appear when you hit the key. However, it is still activem and pressing Return after you hit the key will shut down the system. NOTES o To be considerate to others, please do not run this program on a public machine if you intend to be away from the computer for a significant period of time. Doing so prevents others from being able to use it. This program is intended only to provide the convenience of protecting your work without having to logout so often as you take breaks. o This program is freeware, so you may distribute it as long as your recipients are able to redistribute it freely. Please send comments and bugs to: dayglow@media-lab.mit.edu Your thoughts are much appreciated. Eric Ly
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.