Overview of the software components

The software consists of the seismological part, SeismoGraf, GPSgraf, and SeismoView, and also exploits various software that are included in the MacOS 8.x for network operation and real-time data distribution. Also, the control panel and extension software from National Instruments need to be installed on the Mac that has the A-to-D board.

• SeismoGraf: This is the main program that runs 24 hours a day, each and every day. This program reads in the digitized data from the A-to-D board, displays the current seismogram in a graphics window, "keeps time" by looking for GPS time, or for time marks, or simply uses the Macintosh clock if no external reference time is available. Finally, SeismoGraf writes the seismogram to several different files on your Mac: it writes compressed binary files of the seismogram and the DayView file into local directories, and writes duplicate ASCII versions of these files into sub directories beneath "Web Pages" directory.
   
• GPSgraf: This program also runs 24 hours a day, all the time. It reads in the Garmin GPS II+ GPS receiver output through the modem serial port. If the GPS unit is broadcasting correct absolute time, GPSgraf sends a message to SeismoGraf telling it the precise time (and location of the instrument). It also writes files into the local directory GPSview, which allow for some detailed analysis for absolute time locks. However, for most of the stations, most of the time, SeismoGraf will be locked onto absolute time, and it will note this in the seismogram graphics window.
   
• SeismoView: This is the program used to view seismogram files. The seismogram files may be from the local station on the same Macintosh or from other network stations downloaded through the internet. This program does not have to run on the same Mac that is running SeismoGraf it can run on any Mac, anywhere. SeismoView is the program that will be used every day to look at the DayView and seismogram files produced by SeismoGraf.
   
• National Instruments control panel and extension (NI-DAQ 4.9.x): Just a one-time copy and set-up, then you'll never need to look at these again.
   
• Macintosh Network and Web Server Control Panels: MacOS 8.x makes it easy for the Macintosh to become a web server. All that is needed is a click on a couple of items along with an IP address (assigned by your network administrator).
   
• Web browser (e.g. Navigator or Explorer), bundled with MacOS 8.x: A standard web browser is used to connect to the other OhioSeis stations, via the internet, to download their ASCII seismogram and DayView files. These files can be viewed using SeismoView or, alternatively, they can be loaded into a spreadsheet program.
   
• ResEdit (from Apple): If and when you need to change some SeismoGraf set-up parameters, you will use ResEdit on the "STR#" resource only.