MAG_CD program There are several different formats in use for 1-min. geomagnetic data: these include the WDC-A, WDC-C, WDC-C1, and Scandinavian formats. All of these formats are character formats. We use binary formats, this allows a decrease in the volume occupied by data on disk or tape by approximately a factor of 3. It is considered that character formats are computer independent and binary formats are computer dependent. But, all modern computers have practically the same internal representation of two byte integers and this allows us to use binary integer numbers for data exchange. Full description of the format can be founded in mag_base.txt file. To work with data stored in binary MAG format on CD ROM at IBM-PC compatible computers MAG_CD program is intended. The program creates in current directory file magparam.dat, so the directory from what the program start must be write enable. The program goes straight into the main menu. It is possible to select options either by using the up/down cursor keys to move the highlighted cursor to the desired option and then pressing return or enter, or by typing the capital letter of the option, in which case one is taken straight into the option. As each option is highlighted, a short description of the option is displayed at the bottom of the screen. Some of the options, eg. Mag_WDC, have their own menus, where Quit returns to the main menu. Where there is not an internal menu, press ESCAPE to return to the main menu. Options Select/change database This option is used to select a new working database file. Once this option is selected, you are asked to enter file name or a directory path. If you type directory name (ended by \), a window is laid over the screen, with a list of files. You can select file by using the cursor keys and pressing Enter key. If selected file appears to be a directory a new list will be shown. Pressing Escape key get you back to the main menu. Selecting a new database file takes you to a new screen where you are given information about the data, eg. which stations are represented, as well as the start and end times of the data. Striking any key returns you to the main menu. All other option afterward will be read data from selected file. Look 1 Station Select this option to display and correct data of one selected station (but in this version corrected data do not saved on disk). EGA or VGA monitor is requwied for graphic. The default settings for this option are in square brackets. It is true for all others options. Press F1 key to get help on the option you are being asked about. On the station option, the next option is selected as soon as you type the third letter of the station. If you press * as a station code, you will be requested to enter station code and component character three times. Then you can display components of 3 different stations simultaneously. It is useful to search correlations in events. Press Q or ESC to return to the menu, PgUp, PgDw, left and right cursor keys to scan the dataset, F1 -help. Press L to alter the baselines (the value, which are subtracted from data before plotting), W to select a new station for the plot of the currently selected dataset, E to change the scale of the plot (data unit per pixel). Once the desired 12-hour graph is displayed on the screen, press Z to select the top component, Y, D or B to select the middle component, and X, H or A to select the lower component. You will then be asked " time? ". If you wish to get an explanation of this request , press any key. Enter a figure for the number of hours after the start-time that you wish the high-resolution period to start. The screen will then change color and only one of the traces will be left on the screen. Only 10 hours 39 minutes of data will be displayed. A vertical cursor bar will appear on the left of the screen when a cursor key is pressed or mouse is moved. The cursor can be moved around by using the cursor keys or mouse. The value in nT of the trace under the cursor is displayed, along with the time that the cursor is over, in the top-right of the screen. If you now press Space bar, the time and field value at cursor position are stored and variation from this value will be display additionally. It allows to measure the amplitude of variation. Pressing Space bar next time switch off this option. The cursor can be made to disappear off the screen at top and bottom, but cannot go beyond the limits of the magnetometer trace to the left and right. You can display another component by pressing component character (H, D, Z). To return to the normal plot, press Q or ESC. View Data This option is for displaying up to 10 plots of selected stations and components of magnetometer data, with any number of hours per screen and a more "professional" look than in the first part of " Look 1 Station". The first option line allows to adjust the look of the plot. The meanings of the letters in the first option line are displayed at the bottom of the screen. Y means that this item will by included, N - not included. All other requests also have explanation at the bottom of the screen. You can use ordinary editor keys to edit input line. Press Enter to accept input or ESC to return to the previous request. Type Data Use this option to display 3-channel (H,E,Z) 1-minute data in nu- merical form, as well as other information such as means. Mag-WDC To convert from binary MAG format to ASCII WDC formats (1440 or 400 char/record). Export Extract selected dataset to ASCII string files for using without MAG. Data can be averaged for given intervals. The MAG-CD program intended to display data presented in binary MAG formats recorded at CD ROM is the subset of more powerful MAG program. MAG_CD do not include any operations related with recording data to disk. List of all options of MAG program is in mag_base.txt file. Please mail to vpetrov@charley.izmiran.rssi.ru with any questions and suggestions concerning the program.