SunBlock is a full-featured screensaver application that provides protection from screen burn-in, as well as rudimentary password protection. SunBlock provides similar functionality to programs like After Dark™, but in a smaller package that doesn’t require CDEVs or INITs. I like to keep a copy in my ‘Apple Menu Items’ folder so that I have quick and easy access to screensaving whenever I need it!
SunBlock provides 15 user-selectable screen saver modules. If desired, you can also configure it to monitor mouse movements. In addition, you can add rudimentary security capability by requiring a password entry to change configurations or quit the program (more on these later).
SunBlock 2.2 is actually an updated version of the program ScreenLocker 2.0. Why change the name, you ask? Well, I discovered (quite by accident) that there is already a commercial program called "Screen Locker" in existence, and I decided that I had better change the name! Actually, it's just as well, because I think the name “ScreenLocker” implied a much more limited capability than the program actually had - after all, it makes a fine screensaver in addition to locking the screen (IMHO)! Not that the name “SunBlock” is any more descriptive, but at least it doesn’t give you any preconceived notions (unless you PowerBook users were expecting the program to somehow shield you from the sun’s rays while at the beach <grin>)
For those who used the old ScreenLocker, you’ll find that SunBlock works pretty much the same way, so you won’t have to re-learn anything. See the Quick Instructions, below, to see what has changed.
Like its predecessor, SunBlock is Shareware. I encourage everyone to distribute it freely, using whatever means available (see caveat at the end of this document...) However, if you use SunBlock, I ask that you pay the $5 shareware fee (US currency, please). This one-time payment entitles you to any upgrades that may be developed (depending upon user interest). The honest folks who have already paid the fee for ScreenLocker have my thanks; they do NOT have to pay anything more to use SunBlock.
Read this section to get started right away. More detailed instructions are given a bit later in this document.
SunBlock can create 16 different random screen displays, accessed by the module pop-up menu:
- Filled Ovals
- Filled Rectangles
- Filled Triangles
- Pickup Stix
- Bullseyes
- Color Icons
- Transparent Rects
- Drunken walk (the so-called "random walk" path)
- Unfilled Ovals
- Unfilled Rectangles
- Unfilled Triangles
- Colored Slinkey (zig-zag ‘tubes’)
- Random Letters/Numbers
- The obligatory random stars pattern
- Colored concentric rectangles
- A user-configurable single-line text message
I'll leave it up to you to check out each module to see how they work.
I'll give you a quick hint, though... the Color Icons module uses the 'cicn' resources stored within the program, starting with resource ID 200. If you're handy with ResEdit, you can change the icons to your own favorites. You can also add more icons if you like, numbered consecutively starting at 200, up to 230.
When you run SunBlock for the first time, it will start with the Message module, displaying the message “Welcome to SunBlock. Hit [apple]-C to configure settings”. Check out the different modules by typing [apple]-C to bring up the configuration dialog box. (For those who don't know, the apple key is next to the spacebar.) Select between the various modules via the module popup menu.
You can change the length of time it takes between screen refresh intervals by selecting the "Reblank" popup menu.
If you want to change the program’s preferences, hit the ‘Prefs’ button while the configuration dialog box is displayed. This will let you change the password, require password entry to quit the program or change the configuration, or monitor mouse movement to exit. Note that in order to require password entry to quit or change the configuration, you’ll need to enter an initial password into the program. If desired, do so by clicking the Password button in the Preferences dialog.
If you set up the program to require a password to exit, typing a key or clicking the mouse will bring up a dialog box prompting you for the correct password. Entering the correct password will immediately quit the program; incorrect password entries will cause the program to beep and continue running. With password protection turned on, you must either enter the correct password to quit, or change the configuration preferences to no longer require password entry.
With password protection turned off (the default state), hitting any key or click the mouse button will quit SunBlock.
>>Important Note<<
It is easy for a knowledgable intruder to bypass the password protection. If you're not yet sufficiently knowledgable yourself, I'll let you in on the secret later in this document. I'm working on a more 'secure' version, that doesn't have this limitation, but please be aware that in the meantime, you're not truly locking determined intruders out of your system. Think of it as being similar to locking your car -- these days, that only keeps out the honest folks!
Your module choice, password, and preferences settings are preserved each time you run SunBlock.
Short Cuts:
There are three command key shortcuts. While in screensave mode (with no dialog boxes displayed) type the command [apple] key and the key shown below for the specified result.
Clicking on the SunBlock logo in the configuration dialog box will display these shortcuts, as well as a gentle reminder to pay your shareware fee.
SunBlock is an application, rather than a CDEV or System Extension. (If that doesn't mean anything to you, don't worry about it.) As such, it only offers screen burn-in protection when you specifically activate it. There's no automatic protection after some predetermined period of time. When you want it, just run it!
I like to keep a copy in my "Apple Menu Items" folder, located in the System folder (System 7 users only), so that I have quick, easy access to screensaving and password protection whenever I need it. I also put an alias in my Startup Items folder so that it automatically runs each time my computer starts up.
When you run SunBlock for the first time, it will create a prefs file in the Preferences folder, with the default program settings. Each time you change the program configuration, the prefs file will be updated. Whenever you want to restore the program to its original "factory" settings, just throw away the prefs file. (More on this later...)
SunBlock will start with the Message module, displaying the message “Welcome to SunBlock. Hit [apple]-C to configure settings”. The program will continue to run until you either hit a key or click the mouse. Hitting [apple]-C brings up the following dialog box:
Each of the various items of interest are discussed below:
The module popup menu selects one of the available screensaver modules, listed in the QUICK INSTRUCTIONS section, above. Depending upon which module you select, some additional buttons may be displayed to customize the module. At the present time, only the Message and Letters modules are capable of being customized. Depending upon the level of user interest (translation... depending upon how many REGISTERED users ask for it, hint, hint...), others may be added in the future. If you select the Random Letters module, the Font button is displayed, which will allow you to change the font settings. If you select the Message module, both the Font button and the Message button will be displayed, which will allow you to change the displayed message and the font in which it is displayed.
Hitting the Font button brings up the Font Settings dialog box, shown below. Play with the various settings to come up with something you like.
The reblank interval popup menu selects the time delay before the screen re-blanks itself, starting over with the same module on a black screen.
The Prefs button brings up the Preferences dialog box, shown below:
The default setting for all three check boxes is OFF.
The first check button allows you to turn password protection on or off. With this option off, any key press or mouse click will cause SunBlock to quit. This is useful when you only want to prevent your screen from burn-in, but don't want password protection. This is also useful if you have password protection turned on, but have forgotten your password. If that happens (and you haven't selected the second check box, discussed below), just come back to this dialog box and turn the first check box off. That will allow you to quit the program without having to enter the password.
The second check button allows you to protect your configuration settings by requiring that you enter the password to be able to make changes. (Note that leaving this option off does not provide much protection, though it does simplify things if you have forgotten your password...)
The third check button configures SunBlock to notice mouse movements. With this option turned on, (and no other dialog boxes are on the screen), SunBlock acts as though you had typed a key or clicked the mouse. Therefore, one of two things will happen:
1. If password protection is turned on, the password dialog box will be displayed, prompting you to enter the password to quit the program.
2. If password protection is turned off, SunBlock will quit.
Note that when there is no password stored within the system, the first two check box options are dimmed, indicating that they are not available. You must have a password stored in the system to be able to turn password protection on or off. With no password, both options are forced to off. To enable both check boxes, simply enter a password into the system by pressing the Password button.
Speaking of the Password button, pressing it will bring up the Password entry dialog box, shown below:
If there is currently a password stored in the system, you'll be asked to enter that password first. If no password is currently stored, this step is skipped. Any keystrokes you enter will be echoed as '•' characters on the display. If you are asked for the old password and you enter it incorrectly, SunBlock will beep at you. You'll have to hit the Password button again if you still want to change it. Try again, entering the correct password.
Once you've entered the old password correctly, you'll get another dialog box, asking for your new password. As before, any keystrokes you enter will be echoed as '•' characters on the display. Any combination of characters are allowed. If you've made a mistake, just backspace to the appropriate point, then retype as necessary. Hit <Return> when finished. The system will then ask you to re-enter the new password, in case you inadvertently made a mistake on the first attempt. If both attempts are the same, the new password is accepted. If the two attempts are different, you'll get an error message, and you'll have to start over.
More on passwords...
Before you run SunBlock with password protection, it might be a good idea to save any work you have in progress with other applications. SunBlock doesn't affect any other files or applications that are running, but if you forget your password to exit SunBlock, you may have to re-boot your system and any unsaved work you had will be lost. So, just remember to save your work, and you'll be safe!
While the program is active, and no dialog boxes are displayed, hit any key, or click the mouse, to make the password entry dialog appear, like the one shown below.
Type the password, then hit Return or Enter. SunBlock's passwords are not case sensitive, so any combination of upper- and lower-case characters will work. Any keystrokes you enter will be echoed as '•' characters on the display. If you've entered the password properly, the program will exit gracefully. If not, the screen will be re-blanked, and the SunBlock will continue to run. In that case, just try again. If you make a mistake while typing, use the <delete> key to backspace one character at a time.
That's about it for instructions. Now for some disclaimers, etc...
SunBlock currently needs Color Quickdraw to run. (A few folks have requested a black and white version; Hopefully it'll be out soon.) I have tested it on the Mac II series (II, IIsi, IIci, IIx, IIfx), Performa 550, Quadra 700, and Quadra 650, all using System 7.0 or higher, with excellent results. I've tested it on the Apple 14" and 20" color displays, and the SuperMac 19" grayscale monitor. I haven't tested it on the Classic series, or any PowerBook. I also haven’t tested it with system versions below 7.0, but there’s nothing (that I know of...) in the code that should prevent it from working with System 6. Finally, because I've only tested it on single-monitor systems, I suspect it won't work properly on multiple-monitor configurations (though I'm not sure of that...)
If anyone does test it with System 6, or one of the other Macs I don't have access to, I’d greatly appreciate hearing about your experience!
Naturally, SunBlock does not want to run in the background (what would be the point?) It does allow background processes access to the CPU, but at a slower rate. File sharing activities on networked computers work with no problem. If you have multiple programs running in the background, you'll notice a performance degradation in SunBlock (it'll run slower...). If you want to get rid of that problem, just quit the background programs. Background printing also works, but at the expense of SunBlock's performance.
This software is provided as-is. Use SunBlock at your own risk. There are no warranties or guarantees of any kind, expressed or implied. I am not responsible for any conflict SunBlock may cause with your particular system configuration, or loss of data required if you need to reboot the system without having saved your work on any background applications. I am also not responsible for anyone forgetting their password.
Really, there's not much trouble you can get into with SunBlock, other than forgetting your password.
If that happens, and you haven't turned on the option to require password entry to change configurations, the solution is simple... Just modify your preferences to no longer require password entry! That is, access the configuration dialog by hitting CMD-C, hit the prefs button on the dialog box, then turn off password protection. Accept the changes by hitting OK, then you'll be able to quit the program just by clicking the mouse or typing any letter on the keyboard.
If, on the other hand, you have turned on the option to require password entry to change the program's configuration, type Option-Apple-Esc, all at once. This brings up the Mac's "Force Quit" option, which allows you to exit the program immediately. (This is the secret I alluded to earlier as to how a knowledgable user can easily bypass the password security! I'm still working on a way to disable this function, but it's thus far proven to be quite difficult!!!)
If you quit SunBlock in this way, delete the "SunBlock Prefs" file located in the Preferences folder within the system folder (system 7), or within the system folder itself (system 6). This will restore SunBlock to its original configuration, with password protection turned off, and no password stored within the system. You can then add a new password without having to remember what the old one was.
Alternatively, you can always re-boot your system, but that will also quit any other applications you may have running in the background. For this reason, I recommend saving any work in background applications before running SunBlock, if you want to be extra-careful.
If you have SunBlock in your Startup Items folder so that it’ll automatically run whenever you reboot, then just hold the shift key down while rebooting until you get the “Welcome to Macintosh - Extensions Off” message. After you've rebooted, once again, delete the "SunBlock Prefs" file located in the Preferences folder to restore SunBlock to its original configuration, with password protection turned off, and no password stored within the system.
If you find some other as-yet-undiscovered error in the program, the immediate solution, if you can, is to use the Option-Apple-esc command as discussed above (that is, until I find a way to disable that function!) If that doesn't work, the worst that can happen is that your system will lock up. I have not encountered any such errors during my extensive bug-checking, but a corollary to Murphy's Law says "there's always one more bug!" I would appreciate hearing from you if you find such a problem, so that I can correct it.
I'd like to thank Alex Rampell (AOL: LOTTSIM) for his many helpful suggestions, bug detection, and encouragement during early system development.
SunBlock may be freely distributed via any means, provided:
- All three files (the program, this doc file, and the upgrade history file) are distributed together and unmodified.
- No charge is made for the program itself.
- Companies who charge a fee for distributing shareware/freeware must expressly ask my permission. Please note, however, that I will not grant an exclusive distribution license to anyone (unless, of course, you REALLY make it worth my while <grin>).
I've made a lot of improvements to SunBlock since its original incarnation. As a result, I'm asking a small shareware fee of $5.00 (US). If you like SunBlock, and would like to keep using it, I ask that you please pay for it. Keep shareware alive! Or, if you don’t think a full-fledged screensaver application is worth five bucks, I’d like to know why! Please send me a message (e-mail, postcard, carrier pigeon, etc.), telling me what you think is wrong with it, and I’ll see what I can do.
Please contact me for information about group discounts, site licenses, etc.
Users who have already sent in their shareware fee for any previous version (ScreenLocker 2.0 or SunBlock 2.1) do not need to pay any additional fees. Thanks for your support, folks!
Because I’m charging only $5 per copy, the cost of distributing upgrades by postal mail would be prohibitively expensive. Consequently, I can only send upgrades via e-mail, and I'll only do THAT for registered users. However, anyone can receive the latest version of SunBlock on America Online, or by sending me a STAMPED, self-addressed disk mailer, along with a blank disk.
Send payments, comments, praise, flames, etc., to:
