No. All you need to do is download and install the client software.

About 5 minutes over a 28.8Kbps modem.

SETI@home connects only when transferring data. This occurs once every few days and lasts for about 5 minutes. All of the processing is done off-line.

SETI@home uses a lot of memory while it's running, and it would cause swapping on some computers. We want to make sure it has zero impact on your normal computer work. So, for PC and Mac, the default mode is screensaver.

However, if you already have a favorite screensaver, or prefer not to run a screensaver, SETI@home can also be run as a background program that computes all the time and has no graphics. The UNIX version works like this.

It's not currently fast enough, and there are lots of system-dependent details that we need to handle in C.

The client/screensaver is available for download only from this web page - we do not support SETI@home software obtained elsewhere. This software will upload and download data only from our data server here at Berkeley. The data server doesn't download any executable code to your computer. All in all, the screensaver is much safer than the browser you're running right now!

Not the initial version. Maybe a subsequent one.

We decided not to make source code available for security reasons and for science reasons as well. We have to have everyone do the exact same analysis, or we can't have any control over our research and be confident in our results. We were also worried that there may be a few people that want to deliberately try to screw up our database and server.

Users will not have to do anything if they don't want. The results can be sent automatically, next time the users are on the internet (checking their mail, surfing, etc), or it can be set to ask permission before logging on to the internet.

SETI@home uses the HTTP protocol, and work through any semi-transparent firewall that allows outgoing Web traffic. The latest versions of SETI@home should work through more restrictive firewalls and proxies.

If you are having problems connecting from Windows through a SOCKS proxy, you could also look into SocksCap by NEC at http://www.socks.nec.com/sockscap.html and Hummingbird Socks at http://www.hummingbird.com/products/nc/socks/index.html Both let you use software as if it were "directly connected to the Internet".

If you're STILL having trouble connecting through an HTTP proxy server and you are running SETI@home on an older version of Windows 95, Microsoft has an updated Winsock 2 driver which corrects the problem, and lets the SETI@home client connect. Search for "Windows Socket 2" in the Product Information section of the Microsoft web site. The file is about 986 kbytes, and post-dates Windows 95 Service Pack 1.

Windows software is packaged in files ending with .exe, Mac software with .sit or .hqx, and UNIX with .tar - chances are you have downloaded software for a system other than yours.

On most monitors, no. To make sure, Select the "Go to blank screen" option under Screensaver Settings.

Yes, you can - and as long as you use the same login on each machine, you'll get credit for them all.

Please note that you can (currently) only run one SETI@home process on a Windows or Mac machine (except for the Windows 2000/NT command-line client, which can run multiple processes), and if you are running multiple SETI@home UNIX processes, they must be running out of different directories. To setup these directories simply install the UNIX client as you normally do, but install into a different directory each time. Now you can run multiple SETI@home UNIX processes by starting one instance of the client from each SETI@home directory.

We keep track of every work unit that goes out - if it is taking too long getting the results back, the server will automatically send it out to somebody else. Only after we get results back and confirm them we will remove the work unit from disk.

For quite a while now we have been sending the data out multiple times over the course of a day or so without waiting for a result at all. That allows us to delete the file from our local disks sooner than we otherwise would (as soon as we've received at least two results) and keep our splitters generating data files at a high rate.

Copy any file into your SETI@home Data directory and rename it "stop_after_send.txt". On the Macintosh, the "SETI@home Data" directory is in the Preferences folder, inside your System folder; on UNIX and Windows it is in the same directory as the executable file SETI@home.exe. If you later want to get a new work unit, remove the "stop_after_send.txt" file.

This boils down to the vastly different speeds of different processors. As well, UNIX versions don't have any graphics (yet) and therefore run much faster. You can speed up the Mac and Windows processing by selecting your screensaver to "blank" after a few minutes, thereby reducing the graphics overhead. In addition, there was a bug in early Windows version (before 1.05) that caused it to report incorrect CPU times.

SETI@home does not release detailed candidate coordinates until candidates have been reobserved with sufficient sensitivity to definitively confirm or reject the candidate.

The clients are still looking for Gaussions, however rather than display information about gaussions all the time, in newer clients the information only appears if the client has found a gaussian strong enough to report back to us.

The SETI@home client may be being interrupted by another screen saver or screen saver-like program. As SETI@home is designed to be as noninvasive as possible by only using your computer while it is idle, if the client detects another program that wants to run, SETI@home will quit and step out of the way. If this other program is another screen saver or some other application that waits until your computer is idle before running, both SETI@home and the other program will try to run when the computer is idle causing SETI@home to quit. One common application which shows this behavior is McAfee VirusScan. If you have VirusScan installed, make sure that you have turned off the ScreenScan portion of the application as this will interfere with SETI@home.

A new account must be created from the SETI@home client software (not from the SETI@home website). From the SETI@home client window, select "Settings", then "Change/Create Login". Click "Create New Account" on the pop-up window, and follow instructions from there.

Our screensaver works just like any other screensaver, which includes the ability for the operating system to enforce password protection. This is done through the normal password protection channels.

If you set "Ask me before connecting" in the Preferences dialog, SETI@home will display more detailed information for many errors.

Due to overwhelming interest in the SETI@home project, the server may intermittently be unreachable as too many clients are trying to connect. The server may also be occasionally down for maintainance. If you are unable to connect, please wait an hour and try again.

When we receive the results of a completed work unit at our server, it is transferred to a separate computer for processing. There may be a delay of up to a few days before the results are assimilated and verified. Your credit is updated only after verification of the work unit results data. Once the server has updated your statistics, your computer will receive the revised values the next time it connects to the server. This means that your displayed statistics will generally lag behind the work actually done.

No. You can parallelize SETI@home by running multiple instances of it, either on a multiprocessor or on the nodes of a cluster. Just make sure that each instance runs in a different directory.

Not a graphical one. We may be able to do a command-line (DOS) version.

This is not a SETI@Home bug but a virus ("hybris-b") that causes this behavior. Please download your latest anti-virus updates and disinfect your systems.

Go to the BIOS menus for Configuration and Display.

1. Change the Default Primary Video Device from PCI to AGP, making the internal AGP the boot display device.
2. Change the Boot Display Device from Both (LCD and CRT) to LCD.
3. Turn HV Expansion Off.

Here's one possible solution to the problem, submitted by Ralph Bradley:

"When I got my new PC I transferred my Seti files from the old one. Everything worked. The processing was going 3 times faster then before. Then last August I downloaded a new version of Seti. During installation it flashed a message that my version of Windows did not support the program and then nothing, poof, installation just aborted.
Recently I was browsing through my c:/ directory when I found a small file, OSINFO.ENG, that contained information about my windows, which it identified as Win Mil (rather than Win Me which is what it is). I removed that file and tried the download again. No problems. Seti installed, and has been processing during my down times every since."

In newer versions of Windows, if the screensaver is killed via CTL-ALT-DEL or some other "hard" closing mechanism (typically a crash of some kind), the SAH process still tries to access the graphical application, and unfortunately plants an icon in the system tray _before_ it realizes the app's dead, then keeps repeating the attempt ad nauseum. Moving your mouse over the system tray will make the icons disappear. No performance problems or otherwise. Again, it should only happen if the screensaver app gets killed in an unnatural way.

Yes. In Preferences, select "Data Analysis Always Runs". Select a different screensaver. SETI@home will run, even while the screensaver is running.

In order to protect your account from modification by others, we require both your e-mail address and password for access. If you lose this information, we unfortunately cannot help you access your account or your credits. You will need to create a new account with a valid e-mail address to access any future credit.

Yes. Our software keeps track of where each piece work is done. If your computer is involved in the detection, you will, if you wish, be listed as a co-discoverer.

Due to the large response and the high quality of the data analysis we're going to extend the project past the two year point. We'll also be extending the project to include either data in another frequency band, data from a southern hemisphere observatory, or both.

Our goal is simply to find the signal. If it contains information, it may require experts in linguistics or mathematics to decipher it.

Data is recorded on high density tapes at the Arecibo telescope in Puerto Rico, about one 35 Gbyte tape per day, then mailed to Berkeley, then divided into 0.25 Mbyte chunks which get sent from the Seti@Home server over the internet to people around the world to analyze. Arecibo does not have a high bandwidth internet connection, so data must go by snail mail to Berkeley at first.

No, all computers receive the same size chunks. Faster computers will finish each chunk faster, then immediately get a new chunk to work on, so we'll keep them busy all the time.

We search for strong narrow band signals. It's like tuning your radio set to various channels, and looking at the signal strength meter. If the strength meter goes up, that gets our attention. More technically, it's a lot of digital signal processing, mostly Fourier Transforms at various chirp rates and durations.

We also search for pulsing and drifting signals, and signals which match the antenna beam pattern as the telescope slews across the sky. The analysis software searches for signals about 10 times weaker than any search done to date, because it makes use of a computationally intensive algorithm called "coherent integration" that no one else (including our Serendip program) has had the computing power to implement.

They are merged in a database using our computers here, interference is rejected, and various pattern detection algorithms are applied to search for the most interesting signals.

Yes. Without going into detail (for obvious reasons) we have a mechanism that detects forged results.

See the above question. Besides, it wouldn't matter - if there's a "hit", we will analyze that chunk of data ourselves to verify it.

It's possible. Up to a point, we will handle it by sending the same data to more than one user. Beyond that, if we can afford it, we will set up another data recorder at Arecibo and record a wider frequency range (our current system records only 2.5 MHz out of SERENDIP's 100 MHz bandwidth).

No. The CPU on most computers is always executing instructions (often the operating system's "idle loop") whenever the computer is turned on. It's no additional strain to execute SETI@home.

In response to many requests from our users, SETI@home will now run on systems with screen resolutions smaller than 800X600 pixels. But if the window is larger than the screen resolution, parts of the SETI@home display window may extend off the edge of the screen; if this happens, move the window around to see all the data, or set the display to a higher resolution.

Select the "Blank screen after 1 minute" option under Screensaver Settings, and select "Data analysis always runs" in the Preferences dialog. Minimize the application window.

No. SETI@home writes its results to disk every minute or two.

If time resolution does not yield 64 or more time bins, or if the slew rate is out of bounds, the curve-fitting routine is not called. In the curve-fitting routine, if a Power of Time array has no bin above 3 sigma, skip that array. For each bin (i.e., each candidate Gaussian) if amplitude not above 3.2 sigma (mean recalculated to exclude peak) skip that bin.

Occasionally, a work unit will contain strong radio interference; these strong interfering signals typically come from satellites and radar from our own civilization. If the interference is very strong, the SETI@home program can not analyze that part of the spectrum, and after trying for a few minutes and detecting thousands of strong signals of earth origin, the program stops early in the processing and gets a new work unit. You will still get credit for the work done.

Earth is polluting space with radio and television signals that might be detected by nearby advanced civilizations, but it would be difficult for such a civilization to discover these signals if they only have Earth's current level of technology (eg: if they have an Arecibo like telescope and SETI@home like search).

Early TV shows like I Love Lucy and Ed Sullivan left the earth about 40 years ago, so have gone out 40 light years, reaching several thousand nearby stars. But these signals are relatively weak and SETI@home is not likely to detect the equivalent of Earth type TV transmitters, even on the nearest stars.

Earth's strongest transmitters might be somewhat easier to detect, such as those emitted by military radars, or some radio telescopes. The Arecibo telescope transmits very powerful signals when it is used as a radar system to study planets, asteroids and the ionosphere. These radar signals are powerful enough to be detected 10,000 light years away by searches like SETI@home, except for three big caveats:

a) The Arecibo transmissions are in a very tight beam (they are not omnidirectional, like TV and military radar), so they only cover a very small part of the sky at once (about a millionth of the total sky). It's is unlikely another civilization will be within one of these narrow beams.

b) The Arecibo transmitter's oldest signals left Earth about 30 years ago, so have only travelled 30 light years.

c) SETI@home is not searching the band of frequencies that the Arecibo transmitters utilize (although our older SERENDIP III program did survey one of those bands).

Click on the SETI@home icon in the Menu Bar and select Launch.

First, select "Proxy Settings" from the menu and check that they are correct.

If that is not the problem, then try this: Set "Ask me before connecting" in the SETI@home Preferences. Manually tell your computer to dial the Internet. Then select "Connect Now" from the SETI@home menu while your computer is connected to the Internet. (To dial manually, use the OTPPP, Remote Acess or FreePPP control panel.)

Macintosh dial-up Internet software comes in 2 flavors, Open Transport and FreePPP. On OS 9, Open Transport is called "Remote Access". If you are using Open Transport (OTPPP or "Remote Access"), then:

1) Under the Apple menu, select Control Panels and PPP ("Remote Access" in OS 9). make sure it has the correct phone number of your ISP, login name and password. To connect unattended, you must have "Save password" set.

2) Press the "Options" button, then select the "Connection" tab. Set "Connect automatically ..." and "Disconnect if idle for xx minutes". Set the disconnect delay to whatever number you wish.

3) You may also set the "prompt every xx minutes" checkbox if you wish. If the computer is unattended, so there is no response to the reminder, it will go ahead and disconnect after a few minutes.

If you are using FreePPP, then:

1) Find and open the FreePPP Setup application. Select the "General" tab.

2) Set "Allow applications to open connection" and "Disconnect if idle for xx minutes". Set the disconnect delay to whatever number you wish.

These are disabled while SETI@home is transferring data over the Internet, as they could interfere with the transfer.

Yes. Move the SETI@home icon out of the System Folder : Control Panels folder, to another location (such as the desktop), and restart your Macintosh. You can run SETI@home as a stand-alone application whenever you wish. But if you have another screensaver installed, SETI@home will run very slowly when the other screensaver is active, and the other screensavers animation may be sluggish or jerky.

Response to user input may be a bit sluggish on Macintosh models with slower processors (prior to G3), or with less than 32MB of physical RAM. You may sometimes need to hold the mouse button over the Menu Bar for a few seconds before getting a response.

SETI@home will not launch if another application has a modal dialog frontmost. The Standard File (Open and Save) dialogs are examples of modal dialogs. You must dismiss the modal dialog for SETI@home to launch.

Different portions of the same work unit can vary greatly in speed. If progress seems to freeze, be patient and let it run overnight. It may have gotten past the slow spot by then.

Here are some suggestions:

• Each time SETI@home launches, it optimizes itself for the current monitor color depth (256 colors, Thousands, Millions). If you change the color depth while SETI@home is running, it may slow things to a crawl.
• It should run reasonably at any screen depth, but it will run somewhat faster at lower screen depths (256 colors) than higher ones. Screen resolution (800X600, 1024X732, etc.) should have negligible effect on speed.
• In screensaver mode, SETI@home runs fastest if the screen is blanked, so for maximum speed set the preferences to blank the screen after a short time.
• In application mode, SETI@home runs fastest if its window is collapsed, using the Windowshade feature under OS 8.0 and later.
• Many Macintosh models are equipped with the Energy Saver Control Panel. This can put the computer's processor, hard drive, and monitor in a low-power sleep mode if the mouse and keyboard have been idle for a period of time. Although SETI@home can continue to run when the computer is in sleep mode, it will run much slower. You may want to change the settings in the Energy Saver Control Panel to let SETI@home have more time. Some people prefer to have the computer never sleep so it can analyze more signals, while others prefer to save electricity. The choice is up to you.

Dial-up Internet software comes in 2 flavors, Open Transport and FreePPP. If you are using Open Transport (OTPPP), then:

1) Under the Apple menu, select Control Panels and PPP. make sure it has the correct phone number of your ISP, login name and password. To connect unattended, you must have "Save password" set.

2) Press the "Options" button, then select the "Connection" tab. Set "Connect automatically ..." and "Disconnect if idle for xx minutes. Set the disconnect delay to whatever number you wish. 10 minutes is a good value.

3) You may also set the "prompte every xx minutes" checkbox if you wish. If the computer is unattended, so there is no response to the reminder, it will go ahead and disconnect after a few minutes.

If you are using FreePPP, then:

1) Find and open the FreePPP Setup application. Select the "General" tab. (If you don't see the "General" tab, click the small triangle in the lower left corner.)

2) Set "Allow applications ot open connection" and "Disconnect if idle for xx minutes". Set the disconnect delay to whatever number you wish. 10 minutes is a good value.

1) From the Start button, select "Settings" and then "Control Panels". Open the "Internet Options" Control Panel.

2) Select the "Connections" tab. Make sure the desired "Dial-up networking" selection is set as the default. (The set default button will be grayed out if you select the current default in the list.)

3) Set "Always dial my default connection".

4) Select the correct "Dial-up networking" from the list, and click on the "Settings..." button.

5) Another dialog box "xxxx Settings" appears. Press the "Advanced" button.

6) The "Advanced Dial-Up" dialog will appear. Set "Disconnect if idle for xx minutes" Set the disconnect delay to whatever number you wish. If you wish, you may also set "Disconnect when conection may be no longer needed.

If you set "Ask me before connecting" in the Preferences dialog, SETI@home will display more detailed information for many errors.

First, select "Proxy Settings" from the menu and check that they are correct.

For Windows 95 and 98, do the following steps:

1) From the Start button, select "Settings" and then "Control Panels". Open the "Internet Options" Control Panel.
2) Select the "Connections" tab. Make sure the desired "Dial-up networking" selection is set as the default. (The set default button will be grayed out if you select the current default in the list.)
3) Set "Always dial my default connection".
4) Select the correct "Dial-up networking" from the list, and click on the "Settings..." button.
5) Another dialog box "xxxx Settings" appears. Press the "Advanced" button.
6) The "Advanced Dial-Up" dialog will appear. Set "Disconnect if idle for xx minutes" Set the disconnect delay to whatever number you wish. If you wish, you may also set "Disconnect when conection may be no longer needed."
7) Close the "Internet Options" Control Panel.
8) Double-click on "My Computer", and then on "Dial-Up Networking". Double-click on the default "Dial-up networking" icon. Make sure the "Save password" box is checked. If not, check it and click on "Connect", then "Cancel". Close the dialog.

For Windows NT do this: 1) Click Start, point to Programs, point to Accessories, and then click Dial-Up Networking.
2) Click More, and then click User preferences.
3) In the Enable Auto-Dial By Location dialog box, select each location for which you want the automatic dialing feature to operate.
4) Click OK and then restart the computer.

No. Due to our new security measures to prevent falsified results, if a work unit has been partly completed by a different version of SETI@home, the progress will be reset to zero and the work unit will be processed from the beginning.

After each pass over the data, SETI@home does a preliminary check to see if the data's properties indicate a possible gaussian curve. If not, it saves time by skipping the gaussian analysis. For some work units (those with slow slew rates), no gaussian fit calculations are done for the entire work unit, so this area of the display remains empty.

There are several possibilities. If you have SETI@home set to connect automatically to the Internet, it may have returned the result and gotten a new work unit. (If a work unit has too much radio interference or RFI, then SETI@home may request a new work unit much sooner than usual.)

If SETI@home's processing was interrupted abnormally by a system error or power interruption, its output files may have been corrupted. In this case, SETI@home will restart the work unit from zero automatically.

As of yet, there are no plans to optimize the SETI@home client for any particular platform or processor. Future versions of the client may be optimized, but there are no plans for doing so in the immediate future.

No. The SETI@home installer automatically detects old versions and performs the necessary adjustments.

Yes. Not in 3.0, but in a later version.