Welcome to the Great Internet Mersenne Prime Search! To use this program you must agree to the terms and conditions, prize rules, etc. at http://mersenne.org/legal/ In case you ever forget, the GIMPS web site is at http://mersenne.org My email address is woltman@alum.mit.edu. For networking questions, contact Scott Kurowski at primenet@mersenne.org. FILE LIST --------- readme.txt This file. prime95.exe The program to factor and run Lucas-Lehmer tests on Mersenne numbers. *libgmp* A library file containing the GNU multi-precision math package. On some OSes you may need to copy this the system library directory. whatsnew.txt A list of new features in prime95.exe. stress.txt A discussion of issues relating to stress testing a computer. undoc.txt A list of undocumented and unsupported features. prime.txt A file containing your preferences. The menu choices and dialog boxes are used to change your preferences. local.txt Like prime.txt, this file contains more preferences. The reason there are two files is discussed later. worktodo.txt A list of exponents the program will be factoring and/or Lucas-Lehmer testing. results.txt Prime95.exe writes its results to this file. prime.log A text file listing all messages that have been sent to the PrimeNet server. prime.spl A binary file of messages that have not yet been sent to the PrimeNet server. pNNNNNNN,pNNNNNNN.buN Intermediate files produced by prime95.exe to resume computation where it left off. eNNNNNNN,eNNNNNNN.buN Intermediate files produced during ECM factoring. fNNNNNNN,fNNNNNNN.buN Intermediate files produced during trial factoring. mNNNNNNN,mNNNNNNN.buN Intermediate files produced during P-1 factoring. WHAT IS THIS PROGRAM? --------------------- This program is used to find Mersenne Prime numbers. See http://primes.utm.edu/mersenne/index.html for a good description of Mersenne primes. Mersenne numbers can be proved composite (not prime) by either finding a factor or by running a Lucas-Lehmer primality test. INSTRUCTIONS ------------ There are two ways to use this program. The automatic way uses a central server, which we call the PrimeNet server, to get work to do and report your results. You do not need a permanent connection to the Internet. The second method is the manual method. It requires a little more work and monitoring. I recommend this for computers with no Internet access or with some kind of firewall problem that prevents the automatic method from working. If you are running this program at your place of employment, you must first GET PERMISSION from your network administrator, boss, or both. This is especially true if you are installing the software on several machines. Many companies have policies that prohibit running unauthorized software. Violating that policy could result in TERMINATION and/or PROSECUTION. INSTRUCTIONS FOR THE AUTOMATIC METHOD ------------------------------------- 1) Download and unzip prime95.zip. You've probably done this already since you are reading this file. If necessary install the GMP library (included). 2) Connect to the Internet. Create an account at http://mersenne.org 3) Run prime95.exe. You will see 4 dialog boxes: 3a) In the welcome dialog box, choose "Join GIMPS!". 3b) In the second dialog box, enter your user id and optional computer name. If you are using several computers, use the same user ID but a unique computer name on each machine. An easy-to-remember user ID will be helpful if you plan to visit the PrimeNet server's web page to view reports on your progress. 3c) In the third dialog box, fill in roughly how many hours a day you leave your computer running. Click OK (just close the dialog box on a Mac). 3d) In the fourth dialog box, leave the "Use Primenet..." checkbox checked. Do not turn this checkbox off even if you disconnect from the Internet. Check the "Use a dial-up..." checkbox if you use a modem to connect to the Internet. Note that prime95 will not dial-up to connect to the Internet, rather it waits for a time when you are already connected to contact the server. Click OK. Prime95 will now contact the PrimeNet server to get some work for your computer to do. 4a) If a proxy server is the causing connection troubles, see the later section on "SETTING UP A PROXY SERVER". 4b) If the program will not connect to the server, then you will have to use the manual method described below. 5) Disable screen savers or use the "blank screen" screen saver. If this is not practical, consider raising prime95's priority to 4 or 5. The "Start at Bootup" menu choice (on by default) will run prime95 every time you boot your computer. The "Start at Bootup" choice became "Start at Logon" starting with Windows Vista. MANUAL METHOD INSTRUCTIONS -------------------------- 1) Visit http://mersenne.org/update/ to create a userid for yourself and http://mersenne.org/manual_assignment/ to get an exponent or two to work on. Copy these exponents to a file called worktodo.txt. 2) Run prime95.exe. You will see 3 dialog boxes: 2a) In the welcome dialog box, choose "Join GIMPS!". 2b) In the second dialog box, fill in roughly how many hours a day you leave your computer running. Click OK. 2c) In the third dialog box, uncheck "Use PrimeNet to get work and report results", click OK. 3) Disable screen savers or use the "blank screen" screen saver. If this is not practical, consider raising prime95's priority to 4 or 5. 4) When done with your exponents, use the web pages again to send the file "results.txt" to the PrimeNet server and get more work. The "Start at Bootup" menu choice (on by default) will run prime95 every time you boot your computer. The "Start at Bootup" choice became "Start at Logon" starting with Windows Vista. NOTES ----- Running prime95 may SIGNIFICANTLY INCREASE YOUR ELECTRIC BILL. The amount depends on your computer and your local electric rates. It can take many CPU weeks to test a large Mersenne number. This program can be safely interrupted by using the ESC key to write intermediate results to disk. This program also saves intermediate results to disk every 30 minutes in case there is a power failure. You can compare your computer's speed with other users by checking the web page http://mersenne.org/report_benchmarks/. If you are much slower than comparable machines, utilities such as Task Manager are available that can find programs that are using CPU cycles. You can get several reports of your PrimeNet activity at any time by logging in at http://mersenne.org/. If you have overclocked your machine, I recommend running the torture test for a day. The longer you run the torture test the greater the chance that you will uncover possible problems caused by overheating or overstressed memory. Depending on the exponent being tested, the program may decide that it would be wise to invest some time checking for small factors before running a Lucas-Lehmer test. SETTING UP A PROXY SERVER ------------------------- Choose the "Connection..." button in the Test/Primenet dialog box. Fill in the proxy information. SETTING P-1/ECM STAGE 2 MEMORY ------------------------------ Stage 2 of P-1 factoring step prior to running a Lucas-Lehmer test is slightly more effective if it is given more memory to work with. However, if you let the program use too much memory then the performance of ALL programs will suffer. The good news is that 98% of the time the program uses a minimal amount of memory. In fact, the program will work just fine if you never let it use more than the minimum. So how do you intelligently choose the memory settings? Below are some steps you might take to figure this out: 1) Be conservative. It is better to set the memory too low than too high. Setting the value too high can cause thrashing which slows down all programs. Remember, the program will only use the extra memory in stage 2 of P-1 factoring (about 12 hours a month). 2) Start with how much memory is installed in your machine. Allow a reasonable amount of memory for the OS and whatever background tasks you run (say 100 or 200MB). This represents the maximum value you should use. The program won't let you enter more than 90% of installed memory. 3) Assuming you run your machine 24 hours a day, what hours of the day do you not use your computer? Make these your nighttime hours and let the program use a lot of memory during these hours. But reduce this value if you also run batch jobs at night. 4) Factor in the information below about minimum, reasonable, and desirable memory amounts for some sample exponents. If you choose a value below the minimum, that is OK. The program will simply skip stage 2 of P-1 factoring. Exponent Minimum Reasonable Desirable -------- ------- ---------- --------- 70000000 140MB 440MB 740MB 333000000 620MB 2060MB 3500MB For example, my machine is a dual-processor with 4GB of memory. I guess Windows and the programs I normally use can survive on 512MB of memory. Thus, I set memory to (4096 - 512) or 3500MB. This is my nighttime setting. During the day, I run more programs, so I set memory to 1000MB. I can always stop prime95 if it is doing stage 2 P-1 factoring and I suspect memory is thrashing. More casual users will probably want to set the daytime memory to 8MB so they don't have to worry about prime95 impacting system performance. If at all in doubt, leave the settings at 8MB. The worst that will happen is you end up running a Lucas-Lehmer primality test when stage 2 of P-1 factoring would have found a factor. PROGRAM OUTPUT -------------- On screen you will see: Factoring M400037 to 2^54 is 3.02% complete. Time: 0.121 sec. This means prime95 is trying to find a small factor of 2^400037-1. It is 3.02% of the way though looking at factors below 2^54. When this completes it may start looking for factors less than 2^55. Iteration: 941400 / 1667747 [56.45%]. Per iteration time: 0.109 sec. This means prime95 just finished the 941400th iteration of a Lucas-Lehmer primality test. The program must execute 1667747 iterations to complete the primality test. The average iteration took 0.109 seconds. The results file and screen will include lines that look like: M2645701 has a factor: 13412891051374103 This means to 2^2645701-1 is not prime. It is divisible by 13412891051374103. M2123027 no factor to 2^57, WV1: 14780E25 This means 2^2123027-1 has no factors less than 2^57. The Mersenne number may or may not be prime. A Lucas-Lehmer test is needed to determine the primality of the Mersenne number. WV1 is the program version number. 14780E25 is a checksum to guard against email transmission errors. M1992031 is not prime. Res64: 6549369F4962ADE0. WV1: B253EF24,1414032,00000000 This means 2^1992031-1 is not prime - a Lucas-Lehmer test says so. The last 64 bits of the last number in the Lucas-Lehmer sequence is 6549369F4962ADE0. At some future date, another person will verify this 64-bit result by rerunning the Lucas-Lehmer test. WV1 is the program version number. B253EF24 is a checksum to guard against email transmission errors. 1414032 can be ignored it is used as part of the double-checking process. The final 00000000 value is a set of 4 counters. These count the number of errors that occurred during the Lucas-Lehmer test. M11213 is prime! WV1: 579A579A This means 2^11213-1 is a Mersenne prime! WV1 is the program version number. 579A579A is a checksum to guard against email transmission errors. RUNNING PRIME95 ON SEVERAL COMPUTERS ------------------------------------ The easiest way to do this is to first set up prime95 on one computer. Next copy all the files to the second computer. Delete the local.txt file and worktodo.txt files. These files contain information that is specific to the first computer. Start prime95 on the second computer and use Test/Primenet to give the second computer a unique computer name. Repeat this process for all the computers you wish to run prime95 on. If you do not follow the instruction above, be sure you use Test/Primenet to give each computer the same user id and different computer name. TEST MENU --------- The PrimeNet menu choice identifies your computer to the server. The "Use PrimeNet..." option can be turned on to switch from the manual method to the automatic method. The Worker Threads menu choice is used to choose the type of work you'd like to execute as well as adjust priority and affinity. You should not need to change the priority. You might raise the priority if you just cannot live without a screen saver, or if you are running some ill-behaved program that is using CPU cycles for no good reason. The work type should usually be left set to "Whatever makes the most sense". However, if you are running a slow computer and don't mind waiting several months for a single Lucas-Lehmer test to complete OR you are running a faster computer and get better thoughput if one core does an easier type of work, then choose a different type of work to do. The Status menu choice will tell you what exponents you are working on. It will also estimate how long that will take and your chances of finding a new Mersenne prime. The Continue menu choice lets you resume prime95 after you have stopped it. The Stop menu choice lets you stop the program. When you continue, you will pick up right where you left off. This is the same as hitting the ESC key. The Exit menu choice lets you exit the program. ADVANCED MENU ------------- You should not need to use the Advanced menu. This menu choice is provided only for those who are curious. Note that many of the menu choices are grayed while testing is in progress. Choose Test/Stop to activate these menu choices. The Test choice can be used to run a Lucas-Lehmer test on one Mersenne number. Enter the Mersenne number's exponent - this must be a prime number between 5 and 560000000. The Time choice can be used to see how long each iteration of a Lucas-Lehmer test will take on your computer and how long it will take to test a given exponent. For example, if you want to know how long a Lucas-Lehmer test will take to test the exponent 876543, choose Advanced/Time and enter 876543 for 100 iterations. The ECM choice lets you factor numbers of the form k*b^n+c using the Elliptic Curve Method of factoring. ECM requires a minimum of 192 times the FFT size. Thus, ECM factoring of F20 which uses a 64K FFT will use a minimum of 192 * 64K or 12MB of memory. You can also edit the worktodo.txt file directly. For example: ECM2=k,b,n,c,B1,B2,curves_to_run[,"comma-separated-list-of-known-factors"] The P-1 choice lets you factor numbers of the form k*b^n+c using the P-1 method of factoring. You can also edit the worktodo.txt file directly. For example: Pminus1=k,b,n,c,B1,B2[,"comma-separated-list-of-known-factors"] The PRP choice, available from the menus only in the Mac OS X version, lets you do a probable prime test on numbers of the form k*b^n+c. On all OSes, you can edit the worktodo.txt file directly. For example add: PRP=k,b,n,c[,how_far_factored,tests_saved][,prp_base,residue_type][,"comma-separated-list-of-known-factors"] where the how_far_factored and tests_saved values are used to pick optimal bounds for P-1 factoring prior to running the PRP test. SUM(INPUTS) error checking. Selecting this option will run an extra error check on every iteration. This will slow down the primality test slightly. Round off checking. This option will slow the program down by several percent. This option displays the smallest and largest "convolution error". The convolution error must be less than 0.49 or the results will be incorrect. There really is no good reason to turn this option on. The Manual Communication menu choice should only be used if the automatic detection of an Internet connection is not working for you. Using this option means you have to remember to communicate with the server every week or two (by using this same menu choice). The Unreserve Exponent choice lets you tell the server to unreserve an exponent you have been assigned. You might do this if a second computer you had been running GIMPS on died or if you had been assigned an exponent of one work type (such as a first-time-test) and now you have switched to another work type (such as double-checking). Any work you have done on the unreserved exponent will be lost. The Quit GIMPS menu choice is used when you no longer want this computer to work on the GIMPS project. You may rejoin at a later date. If you are a PrimeNet user your unfinished work will be returned to the server. If you are a manual user, you need to send me email containing your results.txt file. OPTIONS MENU ------------ The CPU menu choice tells you what CPU the program has detected and lets you set how much memory the program can use (see the earlier section on "Setting available memory". The Preferences menu choice lets you control how often a line is written to the main window and how often a line is written to the results file. It also lets you change how often intermediate files (to guard against power failure and crashes) are created. You can control how often the program checks to see if you are connected to the Internet. The program polls whenever it has new data to send to or work to get from the PrimeNet server. If you are low on disk space, you can select one intermediate file instead of two. However, if you crash in the middle of writing the one intermediate file, you may have to restart an exponent from scratch. You can also tell the program to be quiet, rather than beeping like crazy, if a new Mersenne prime is found. You can also make prime95 go idle whenever your laptop is running on battery power (may not work under Windows NT/2000/XP). The Torture Test choice will run a continuous self test. This is great for testing machines for hardware problems. See the file stress.txt for a more in-depth discussion of stress testing and hardware problems. The Benchmark choice times the program on several FFT lengths. You can then compare your computer's speed to others list at http://mersenne.org/report_benchmarks/ The Tray Icon choice will cause prime95 to have a small icon on the taskbar when it is minimized. You can activate or hide the program by double-clicking on the small icon. If you place the cursor over the small icon, a tooltip will display the current status. The No Icon choice is only enabled if the Advanced Menu is activated with the password. Using this menu choice means there will be no prime95 icon on the taskbar once you minimize the program - making it very hard to reactivate! You can reactivate the program by trying to execute prime95 a second time. Alternatively, you can turn this feature off by editing prime.txt and change the line "HideIcon=1" to "HideIcon=0", then reboot. Checking the "Start at Bootup" menu choice will run prime95 as a service that starts when your computer boots up. Windows NT/2000/XP users need administrator privileges to use this feature. Vista has eliminated support for running prime95 as a service. Running prime95 as a service is better than creating a shortcut to prime95 in the startup folder because services run even when no one is logged on. These are the details you should be aware of: In Windows 95/98/Me: The HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunServices registry entry is created. You will not be able to tell any difference between prime95 running as a service and prime95 running as an ordinary process. Windows Vista/7/8 and Windows NT/2000/XP without admin privileges: In this case the menu text is changed to "Start at Logon". The HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run registry entry is created. Prime95 will run only when you are logged in. In Windows NT/2000/XP with administrator privileges: There are a few minor quirks when running as a service. You shouldn't run into these quirks in normal operation. You can only change this option once and it will take effect when you exit the program. The prime95 window will only appear on one user's desktop. Finally, if you are worried about giving users access to a GUI service running in the Local System account, you can turn off the "Allow service to interact with desktop" option in the services control panel applet or run the GUI-less NT service version available at http://www.mersenne.org/download/ These options are more secure than using the No Icon menu choice. COMMAND LINE ARGUMENTS ---------------------- -An Obsolete. This is used to run two or more copies of prime95 from the same directory. Using this command line argument causes prime95 to use a different set of filenames for the INI files, the results file, the log file, and the spool file. Just use a different value of n for each copy of prime95.exe you start. -t Run the torture test. Same as Options/Torture Test. -Wdirectory This tells prime95 to find all its files in a different directory than the executable. POSSIBLE HARDWARE FAILURE ------------------------- If the message "Possible hardware failure, consult the readme file." appears in the results.txt file, then prime95's error-checking has detected a problem. After waiting 5 minutes, the program will continue testing from the last save file. The two most common errors messages, SUMINP != SUMOUT and ROUND OFF > 0.40, are caused by one of two things: 1) For reasons too complicated to go into here, the program's error checking is not perfect. Some errors can be missed and some correct results flagged as an error. If you get the message "Disregard last error..." upon continuing from the last save file, then you may have found the rare case where a good result was flagged as an error. 2) A true hardware error. If you do not get the "Disregard last error..." message or this happens more than once, then your machine is a good candidate for a torture test. See the stress.txt file for more information. Could it be a software problem (bug)? Unlikely. Try running a torture test and/or asking for advice at mersenneforum.org. Running the program on a computer with hardware problems may produce incorrect results. This won't hurt the GIMPS project since all results will be double-checked. However, you could be wasting your CPU time. If you are getting errors during primality tests, then I recommend changing to PRP testing which has an extremely robust error detection and correction mechanism. LUCAS-LEHMER DETAILS -------------------- This program uses the Lucas-Lehmer primality test to see if 2**p-1 is prime. The Lucas sequence is defined as: L[1] = 4 L[n+1] = (L[n]**2 - 2) mod (2**p - 1) 2**p-1 is prime if and only if L[p-1] = 0. This program uses a discrete weighted transform (see Mathematics of Computation, January 1994) to square numbers in the Lucas-Lehmer sequence. COPYRIGHTS (hwloc library) -------------------------- Copyright © 2004-2006 The Trustees of Indiana University and Indiana University Research and Technology Corporation. All rights reserved. Copyright © 2004-2005 The University of Tennessee and The University of Tennessee Research Foundation. All rights reserved. Copyright © 2004-2005 High Performance Computing Center Stuttgart, University of Stuttgart. All rights reserved. Copyright © 2004-2005 The Regents of the University of California. All rights reserved. Copyright © 2009 CNRS Copyright © 2009-2016 Inria. All rights reserved. Copyright © 2009-2015 Université Bordeaux Copyright © 2009-2015 Cisco Systems, Inc. All rights reserved. Copyright © 2009-2012 Oracle and/or its affiliates. All rights reserved. Copyright © 2010 IBM Copyright © 2010 Jirka Hladky Copyright © 2012 Aleksej Saushev, The NetBSD Foundation Copyright © 2012 Blue Brain Project, EPFL. All rights reserved. Copyright © 2013-2014 University of Wisconsin-La Crosse. All rights reserved. Copyright © 2015 Research Organization for Information Science and Technology (RIST). All rights reserved. Copyright © 2015-2016 Intel, Inc. All rights reserved. THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. COPYRIGHTS (QD - QUAD-DOUBLE/DOUBLE-DOUBLE COMPUTATION PACKAGE) --------------------------------------------------------------- Copyright (c) 2003, The Regents of the University of California, through Lawrence Berkeley National Laboratory (subject to receipt of any required approvals from U.S. Dept. of Energy) All rights reserved. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. COPYRIGHTS (libcurl) -------------------- Copyright (c) 1996 - 2016, Daniel Stenberg, daniel@haxx.se, and many contributors, see the THANKS file. All rights reserved. Permission to use, copy, modify, and distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. COPYRIGHTS (libgmp) ------------------- Copyright 1991, 1996, 1999, 2000, 2007 Free Software Foundation, Inc. This file is part of the GNU MP Library. The GNU MP Library is free software; you can redistribute it and/or modify it under the terms of either: * the GNU Lesser General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. or * the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. or both in parallel, as here. The GNU MP Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received copies of the GNU General Public License and the GNU Lesser General Public License along with the GNU MP Library. If not, see https://www.gnu.org/licenses/. OUR DISCLAIMER -------------- THIS PROGRAM AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE. THANKS ------ Happy hunting and thanks for joining the search, George Woltman woltman@alum.mit.edu