The Mapper Program Version 1.7 22 November 1988 I was interested in techniques for producing maps, and found the article by William D. Johnston in the May and June 1979 Byte Magazine. This two part article provided an excellent introduction and source code in Basic Language. His code was restricted to the algorithms and did not get involved with user interface. To evaluate his algorithms and try out the displays I coded the program and a simple interface in Turbo-C Version 1.5. The program in its current form is highly based on Mr. Johnston's algorithms and provides no significant additional capabilities. I also found a high resolution database called the Micro World Data Bank II (MWDBII). This database was 1 megabyte in length and good down to minutes of a degree. See the C source code comments for availability. To run the program and receive help you use the DOS common method of the question option "/?". Just type "mapper/?" and the following usage help will be displayed: Usage: mapper [/bcdgilmrsx] /b Boundaries Off /c Countries On /dn Database ('MWDBII' Default) /g Grid lines On /i Islands Off /l Lakes Off /mn Map Resolution (5 Default) /r Rivers On /s States On /x Colors On Defaults to Boundaries and Islands On The defaults are what I thought should be fairly common. The map database has 5 resolutions, and can be selected with the 'm' option. 5 is the lowest resolution and 1 is the greatest. If you have several different databases you can use the 'd' option and provide the path and filename (128 Characters max). The 'm' and 'd' options should be placed at the end. They can be put anywhere but it's a little easier at the end. Example: mapper/glrsm1. If you use the option in the middle you will need to put a space between it and the remaining options. Example: mapper/glddata /rs. These are the most foolproof methods. Note: The level 5 database included doesn't really use the options yet. The program works as advertised on level 1. There are some errors with the database as you'll see. I've converted the database to ASCII, and am working on cleaning up the errors and redundancies. A little about the speed of the result. The program is quite slow on an 8088 without a math coprocessor, and speed is getting acceptable on an 80286. The C language standard uses double precision math. This is a waste with the current database resolution. An integer version of the math routines would sure speed up the program quite a bit. The mapper program uses Turbo-C auto detect of a math coprocessor and graphics device type (CGA, EGA, and VGA). If you want to quit the plotting on the screen, just hit any key and the bell will sound and exit you back to DOS. You can also use Control-C to get out. The C program lists three sources for the Micro World Data Bank II database. The database is 1 Megabyte (800K Compressed) and is just too much data for reasonable downloading. To see if the program would be useful for you I included a level 5 resolution map (the lowest resolution). This particular database has all the data thrown together so the command line options aren't fully functional. They become functional at about level 3 I believe. This program was tested on a PC XT Clone, 640K, and NSI EGA board. Also a Zenith Z-248 with 512k and CGA was tested. Other configurations will need to be tested. Due to the grid method used, it shouldn't be used with an Azimuthal Equidistant map. You can try it once to see what I mean. There's lots of room for improvements, "Handle It!". Thanks to Mr. Johnston for his article and algorithms. USMail: Steve R. Sampson, Box 45668, Tinker AFB, Oklahoma, 73145 Compuserve: 75136,626 Unix: sampson@killer.dallas.tx