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Text File | 1989-09-18 | 25.8 KB | 519 lines

TIMEGEN.EXE Version 1.0 A program for generating time signals in Naval Observatory format Copyright 1989 Life Sciences Editorial Services 1236 River Bay Road Annapolis, Maryland 21401 SHAREWARE NOTICE TIMEGEN IS NOT A FREE PROGRAM AND IT IS NOT GIVEN TO THE PUBLIC DOMAIN. IT IS SHAREWARE, WHICH MEANS YOU ARE REQUESTED TO COMPENSATE THE AUTHOR FOR HIS EFFORTS IF YOU CONTINUE TO USE THE PROGRAM. THOUGH REGISTRATION AND PAYMENT ARE EXPECTED IF YOU DECIDE TO KEEP AND USE TIMEGEN, THE PROGRAM IS NOT "CRIPPLED" IN ANY WAY TO COERCE YOU TO PAY BEFORE GETTING A FULLY IMPLEMENTED VERSION. THE FULLY IMPLEMENTED VERSION IS IN YOUR HANDS RIGHT NOW, AND IT IS ASSUMED THAT YOU ARE HONORABLE AND WILL PAY FOR IT IF YOU CONTINUE USING IT AFTER A 14-DAY TRIAL. DETAILS ON REGISTRATION ARE PROVIDED NEAR THE END OF THIS DOCUMENT. DESCRIPTION TIMEGEN.EXE is a program that generates and transmits time signals in Naval Observatory format to computers running Professional TIMESET (TIMESET version 5 or higher). The purpose is to make it unnecessary for all the computers in a local system to call the Naval Observatory for accurate time. Only one of the computers needs to do it. After that computer's clock has been synchronized with the Naval Observatory, TIMEGEN synthesizes accurate time data strings that other computers, calling it with Professional TIMESET, can use to set their own clocks. The benefit (for all but the relatively small number of people for whom the Naval Observatory is a local call) is that a single long distance phone call allows several computers to become closely synchronized with the cesium clocks of the Naval Observatory and with each other. The program should be especially useful for large organizations, especially those using computer programs that time-stamp data in files. For example, it would seem highly desirable for all the personal computers on a military base to be set to the same time. Likewise, all the branch offices of banks and other corporations probably need to have their computer clocks synchronized. The same goes for all the stations of a state police system. All such organizations now have that potential with TIMEGEN. In effect, the program allows organizations to create specialized computer bulletin boards to act as local "substations" of the U.S. Naval Observatory. Several options are available for defining the program's period of operation. It can be set up to run for an indefinite time, between specific times of the day, for a specified length of time irrespective of actual time, or continuously with periodic updates from the Naval Observatory to correct drifting of the host computer's clock. CONFIGURING THE PROGRAM TIMEGEN is a self-configuring program; that is, it writes your input for time zone, time season (daylight or standard), communication port number, and monitor type to its own source file on disk, thus eliminating the need for an external configuration data file. Your configuration becomes a semi-permanent part of the program itself. Reconfiguration is extremely simple, requiring only a switch on the command line to force configuration mode. There are only four substantive prompts to answer during configuration, and three of them require pressing only a single key. If your copy of TIMEGEN has never been configured before, it will automatically load in configuration mode the first time you run it. It seems unlikely that a copy you obtained from a computer bulletin board will not be configured, however, since responsible sysops usually test programs they receive before making them available for downloading. The chances are, then, that the program will immediately start running as soon as you enter TIMEGEN in DOS and press return. If the program has been previously configured, there is a good chance that the configuration will not be right for you. The time zone might not be yours, or the time season might have changed, or you are using a different serial port, or you have a monochrome system and the program has been preconfigured for color (or vice versa). For this reason, you should run TIMEGEN in configuration mode the first time you use it. To configure, you have to be in the same drive and directory as the program itself; you can't do it from any other drive and directory. Once you're in TIMEGEN's drive and directory, type the following at the DOS prompt: timegen /c The /C tells the program you want to configure. The four questions you have to answer are easy ones, and explanation is provided on the configuration screen itself for one of the questions. The first question is the only one that requires some thought (and very little at that). It has to do with your time zone. What is required here is a number representing the hours difference between your local time and the time in Greenwich, England (0 degrees longitude) when both places are under STANDARD time. Examples are provided for all four time zones in the contiguous United States. Don't try to make any adjustment here if you are on daylight time; the very next question will ask if you're on daylight time, and the program itself will make the necessary adjustment if your answer is yes. Another point: for time zones west of Greenwich it is absolutely essential that the number you enter be preceded by a minus sign. A final point on the time zone setting: if the host computer's clock is set to universal time (which can be done automatically by calling the Naval Observatory with TIMESET configured for universal time), the offset to enter in response to the time zone prompt is 0. Some organizations, notably airlines, are run on universal time, and it's likely that many of their computers are set to it. If the host computer is on universal time, you must not choose daylight time at the next prompt because there are no seasons to universal time; there is no such thing as "universal daylight time." Unlike civil time, universal time does not "spring forward" and "fall back" with the change of seasons, it's always standard time. The only question about your modem pertains to the port to which it is attached. Other modem settings, including baud rate (1200), parity, data bits, and stop bits, are built into the program and are not configurable. You have a choice of COM1, COM2, COM3, or COM4 and you make it by typing 1, 2, 3, or 4. There are factors that limit the choice of COM3 or COM4, however. COM1 and COM3 can't be used at the same time, and COM2 and COM4 can't be used at the same time. Thus, if you have a serial mouse attached to COM1, you may configure TIMEGEN to use a modem attached to either COM2 or COM4, but you can't have a modem (or any other device) on COM3. And if you have a mouse on COM2, you may configure TIMEGEN to use a modem attached to either COM1 or COM3, but not to COM4. The technical reason for this is that a PC does not have enough IRQ (interrupt request) lines to support four COM ports simultaneously and independently. COM1 and COM3 have to share one line and COM2 and COM4 have to share another, and you can't have two devices using the same IRQ line. This is a limitation of the PC, not of TIMEGEN. If the program detects the presence of a serial port mouse in a multiple port system during configuration, it will indicate which COM ports may not be used for the modem. The last question is about your monitor. You can have either a color or monochrome display if you have a color system. If you have a monochrome video adapter, you will get a monochrome display no matter what you choose here. A final prompt asks whether your configuration is OK. If you respond by typing "y" the configuration is written into a special buffer in the program's own disk file and the newly configured program is automatically reloaded. If you type "n," the configuration procedure starts over. It's extremely simple to reconfigure this program. Most likely you will have to do it only twice a year to adjust for changes between standard and daylight time. Once TIMEGEN is configured you can run it from any directory, provided you have created a path to it by means of the DOS PATH command. You will also need a path to Professional TIMESET since TIMEGEN needs to run that program through a shell. ROUTINE OPERATION TIMEGEN cannot function properly without TIMESET. You will need both programs. Furthermore, TIMESET must be version 5 or higher (Professional TIMESET). Likewise, callers will not be able to access TIMEGEN with versions of TIMESET earlier than 5. The reason is that the earlier versions have the Naval Observatory's phone number built into their code, whereas Professional TIMESET allows the user to enter any phone number (except mine). Professional TIMESET (ver. 5 or later) is available for downloading as shareware from Compuserve and many computer bulletin boards. It can also be obtained directly from Life Sciences Editorial Services, 1236 River Bay Road, Annapolis, Maryland 21401 (single user charge: individuals $35, institutions $75; special licensing is required for institutions making multiple copies for use on more than one computer). This section describes several ways of operating TIMEGEN. Since the purpose of the program is to provide an accurate time standard for other computers, it is obvious that no matter what operating mode is selected, the source computer's clock needs to be as accurate as possible. TIMEGEN makes this easy by automatically running Professional TIMESET to call the Naval Observatory before starting to generate its own time signals. Furthermore, if TIMEGEN is loaded for continous long-term operation, the computer clock will be kept highly accurate by periodic calls to the Naval Observatory (calling interval is determined by the user). These clock updates in the source computer are accomplished by an automatic shell to TIMESET. The total amount of memory required for TIMEGEN and the shell to TIMESET is less than 145 kbytes (TIMEGEN requires about 51 kbytes and Professional TIMESET requires about 89 kbytes). After the initial call to the Naval Observatory is completed and the computer's clock is updated, TIMEGEN opens the designated serial port in answer mode, waits for incoming calls from computers calling with Professional TIMESET, and continuously displays Naval Observatory-style time data strings as it waits. As soon as connection is established, TIMEGEN will start sending the time data strings over the line to the calling computer. The strings will have exactly the same form as the Naval Observatory's data strings: <cr><lf>jjjjj ddd hhmmss UTC<cr><lf>* where <cr> stands for carriage return; <lf> stands for line feed; jjjjj is the truncated number of the Julian day at Greenwich, England (the true Julian day would have the same number preceded by 24); ddd is the day of the year at Greenwich; and hhmmss stands for hours, minutes, and seconds at Greenwich. The letters UTC stand for coordinated universal time. The asterisk marks the instant when the time changes to the universal time just announced in the same data string. A universal time data string of this form is synthesized by TIMEGEN every second and part of it (jjjjj ddd hhmmss) is displayed on the screen in large numbers that change every second, whether or not a caller is on line. To synthesize these strings, TIMEGEN makes use of the computer's clock and the time zone and time season information you supplied at configuration. Each string displayed is what will be sent next, and therefore will be 1 second ahead of local seconds (local time is also displayed continously, in smaller numbers). If a call is in progress, all the string characters except the asterisk are sent through the modem as soon as they are synthesized. Then there is a slight pause as the program waits for the second to change. The asterisk is sent at the instant the second changes, and the word "Sent" flashes simultaneously at the right side of the screen. The calling TIMESET program reacts to the arrival of the asterisk by immediately setting the calling computer's clock to the time just announced by TIMEGEN, after making adjustments for local time zone and time season. The whole process is precisely orchestrated, but the results can be no more accurate than the accuracy of the host computer's clock. As noted, high accuracy in the source computer's clock is ensured by automatic shells to TIMESET while TIMEGEN is running. The interval for these automatic clock updates is set by the user at the time of loading, and the choice depends on the stability of the computer's clock, the amount of time drift that can be tolerated, and how long TIMEGEN will be run. If your computer gains 0.1 second per hour, as mine does, and accuracy within half a second is acceptable to you, you won't have to redial the Naval Observatory for 5 hours. You wouldn't even have to do that if you wanted TIMEGEN to run for 5 hours or less. Indefinite Period of Operation The simplest way to run TIMEGEN is by typing its name in DOS and pressing return. When loaded this way, the program will synchronize with the Naval Observatory then wait for timesetting calls until the ESC key is pressed to make it stop. The time will probably have adequate accuracy if the run period is not too prolonged (you'll need to experiment to find out what is "too long" for your own computer clock). If TIMEGEN is to be run for several hours, however, this is not the best way to do it. A method to be described a little later is far better because it provides automatic updating of the host computer's clock by periodic calls to the Naval Observatory. Automatic Operation Between Designated Times Two command line switches, STARThh:mm:ss and STOPhh:mm:ss, are available for defining a specific period of operation during which TIMEGEN will respond to incoming calls. For example, if you wanted to set up TIMEGEN to respond to calls between midnight and 8 am, you could enter the following at the DOS prompt: timegen start00:00:00 stop08:00:00 Notice that there must be no space between START and its numbers and between STOP and its numbers. They must be run together as shown. Notice also that times must always be entered in DOS's 24-hour format, where 1 p.m. is 13 hours, 11 p.m. is 23 hours, and midnight is 0 hours. Actually, it can be even simpler than that, because you don't have to enter values for minutes and seconds in this situation where you start and stop on the hour. Thus the following would also work: timegen start0 stop8 Nor do you have to use seconds in the start and stop times if don't want to. A command like this will also work: timegen start0:30 stop08:30 The program will load immediately, but it will wait until the designated starting time (local time) before dialing the Naval Observatory for an initial timeset. Then it will open the serial port, put the modem into answer mode, and continuously display the local time as it waits for calls. At the stop time it will restore the modem to its default settings, close the port, and exit to DOS. What if someone is on line when it's time to shut down? Do they get cut off? No, the stop time is automatically incremented second by second until the call is completed, then the shut-down occurs. Operation for a Specific Period of Time An alternative method of timed operation is simply to specify how long the program should run. This is done by using the word PERIOD on the command line. Thus, if you wanted the program to run for a period of two and one-half hours then quit, you would type the following in DOS (with no spaces inside the command line switch): timegen period2.5 The number of hours can range from 0 to 24. The fractions of hours can only be .25, .50, or .75, that is, 15-minute blocks. Any other fractions will be ignored. The START switch can be used in combination with PERIOD to make the program wait until a starting time before opening the port. Here is a command that would load the program, make it wait until 8:15 p.m. to start, stay available for sending time signals for 4.25 hours, then shut down (at a half hour past midnight): timegen start20:15 period4.25 Don't bother putting in the STOP switch if the PERIOD switch is present. The STOP switch is ignored in that situation. Full-Time Operation with Periodic Naval Observatory Updates If you are willing or need to dedicate a computer to prolonged full-time generation of Naval Observatory time signals of the highest accuracy, you can do that too with TIMEGEN working in combination with Professional TIMESET. The minimal command line switches needed for full-time operation are CONTINUOUS and PERIODnn.nn Thus the following command would cause continuous operation with automatic update calls to the Naval Observatory every 4 hours: timegen continuous period4 The cycle will go on endlessly until you press the ESC key while in TIMEGEN. Additional variations are possible. For example, the START switch can be used together with CONTINUOUS and PERIODnn.nn to make TIMEGEN wait until a certain time before starting continuous operation with periodic clock updates from the Naval Observatory. It is also possible to enter options on TIMEGEN's command line that will control the operation of Professional TIMESET during the periodic updates. For example, Professional TIMESET can do remote digital loopback (RDL) tests to measure and correct for signal delays (most useful for satellite links). However, both modems must be capable of doing the test. Furthermore, the modem that TIMEGEN is using must be configured to grant the RDL request from the calling modem. This is best done by using a standard communication program to write the configuration into the modem's nonvolatile memory; the command is AT&T4&W. (Hayes 2400 Smartmodems are configured at the factory to grant an RDL request from a remote computer, but other brands may not be.) A full discussion of Professional TIMESET's command line switches is beyond the scope of this document -- you'll need to get Professional TIMESET anyway -- but all of them can be passed to Professional TIMESET by putting them on TIMEGEN's command line preceded by the word TIMESET. For example, if you wanted TIMEGEN to run continuously, with a shell to TIMESET every 5 hours for automatic Naval Observatory update, and with correction for signal delay, you would type the following: timegen continuous period5 timeset/l /L is the command line switch that tells Professional TIMESET to do a remote digital loopback test and calculate signal delay. Please note that the word TIMESET is simply a flag to announce command line switches that are to be passed to TIMESET when TIMEGEN runs it. If you don't want to pass any switches to TIMESET, you don't need to put the word TIMESET on the command line (TIMESET will be run anyway, in bare bones automatic fashion). The periodic calling of the Naval Observatory in the continuous mode of operation ensures that time signals sent to other computers by TIMEGEN will always be very close to the true time. In fact, with sufficiently frequent update calls to the Naval Observatory, TIMEGEN's signals can be made practically as accurate as those obtained from the Naval Observatory itself. For example, since my computer's clock gains about 0.1 sec per hour, I could maintain 1-second accuracy by calling the Naval Observatory with TIMESET every 10 hours, 0.5-second accuracy by calling it every 5 hours, 0.1-second accuracy by calling it hourly, and 0.05- second accuracy by calling it every 30 minutes. A NOTE ON ACCURACY Clearly, the greater the accuracy desired the more frequently the Naval Observatory has to be called. You'll need to decide what level of inaccuracy is acceptable and adjust TIMEGEN's frequency of calls to the Naval Observatory to achieve that level. Striving for extreme accuracy can require a lot of long-distance calls, depending on the stability of the host computer's clock. On the other hand, you may need to consider how many more long distance calls would have to be made if, say, 25 computers in an organization that could be served locally by TIMEGEN were instead to call the Naval Observatory several times a day to maintain the same degree of accuracy. Here is a suggestion for fearless souls who know their way around the inside of a computer (others should not try it!). It is possible, on some computers anyway, to fine tune a computer's clock by adjusting a set screw near the clock chip, which is usually located on the bottom side of the mother board. With computers that have this feature, a daily small (very small!) incremental adjustment followed by delayed observation of effects on clock accuracy (checked with Professional TIMESET, of course, since it can create a log file to save your before-after system clock readings for analysis) should eventually lead to a significant improvement in the computer clock's accuracy and a corresponding reduction in the required frequency of update calls to the Naval Observatory. It would seem advisable to make a micro adjustment and wait a full day before checking the results, then make another micro adjustment if necessary and wait another full day to measure the change, and continue this way until you are satisfied that the clock can't be made any more accurate. (It's certain that it will never be perfect, because the clock speed can be affected by temperature variations. That's why places like the Naval Observatory and the National Bureau of Standards use hugely expensive atomic clocks.) Going to these lengths to achieve extreme accuracy for TIMEGEN is probably not necessary for most situations. Most organizations will probably be quite satisfied to have their TIMEGEN-equipped host computer and all their other computers within one second of true time. With a reasonably well behaved computer clock, TIMEGEN can achieve that with maybe a couple of well spaced calls to the Naval Observatory each day. SHAREWARE REGISTRATION If you like TIMEGEN and continue to use it after a reasonable trial period (14 days), you should pay for it. The price is $25 for a single copy for a single machine (with only backup copying). Special licensing is required for institutional users who make copies for use on more than one computer (contact the author at the address shown below). Your registration will contribute to the program's further development, and it entitles you to one free upgrade on diskette when available and advice by telephone (your call) if you run into problems. The address for registration and for licensing inquiries is: Peter L. Petrakis Life Sciences Editorial Services 1236 River Bay Road Annapolis, Maryland 21401 Please make your check or money order payable to Peter L. Petrakis and include your name, address, zip code, and phone number. Thanks. TIME GENERATOR REGISTRATION FORM (Institutions using multiple copies of TIMEGEN on multiple computers should not use this form; instead contact Life Sciences Editorial Services for site licensing arrangements.) To: Peter L. Petrakis Life Sciences Editorial Services 1236 River Bay Road Annapolis, Maryland 21401 I enclose payment for registration as a user of TIMEGEN.EXE. YOUR NAME: ________________________________________________________ YOUR ORGANIZATION:_________________________________________________ YOUR ADDRESS: _____________________________________________________ _____________________________________________________ CITY, STATE, ZIP ____________________________________________ YOUR PHONE: (____) ____ ______ METHOD OF PAYMENT (Check one) Check ___ Money Order ___ AMOUNT ENCLOSED (the $25 price entitles you to make copies of TIMEGEN for backup purposes for use on a single machine only) $25 ___ YOUR SIGNATURE: ________________________________________ DATE: ____________ RESTRICTIONS AND DISCLAIMER TIMEGEN.EXE and this document are copyrighted, with all rights retained by their author, Peter L. Petrakis, Life Sciences Editorial Services, 1236 River Bay Road, Annapolis, Maryland 21401. The program may be freely distributed provided (1) this document always accompanies it and (2) neither the program nor this document is altered in any way. TIMEGEN.EXE and its documentation are NOT donated to the public domain, and no one besides their author is allowed to sell, solicit payment for, or modify them. Distributors of shareware, freeware, and public domain programs who charge only a modest disk copy fee to cover distribution expenses are permitted to distribute these files. Violation of these terms is an infringement of copyright under the laws of the United States and associated international treaties. Although TIMEGEN.EXE has been extensively tested, Peter L. Petrakis makes no warranty concerning the program's fitness or safety, and he accepts no responsibility or liability for any kind of mishap resulting from its use. Your use or distribution of the program implies your acceptance of all these terms.