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- SWIVEL USER'S GUIDE (VERSION 1.0)
-
- Ken Van Camp
- P.O Box 784
- Stroudsburg, PA 18360
-
- SWIVEL stands for "Simple World Interactive Viewing Enhanced Library",
- and is an interactive program to allow viewing of "The World Digitized",
- Copyright (C) John B. Alison. It will "let your fingers do the walking"
- across the world on your computer. While SWIVEL is placed in the public domain
- and is freely distributable, the data for the The World Digitized is not.
- Read Mr. Alison's documentation (READ.ME) for details on payment. I highly
- recommend that anyone that uses SWIVEL send Mr. Alison the $20 donation he
- requests -- this database represents an awful lot of work!
- SWIVEL is, as its name says, simple. It represents only about level
- III in the suggested program by Mr. Alison. SWIVEL runs on IBM PC-compatible
- computers WITH AN EGA-COMPATIBLE GRAPHICS ADAPTER. SWIVEL must have an
- EGA to work; it will probably hang a computer with the standard CGA or
- Hercules type card.
- Using SWIVEL is simple. You start it up by just typing 'SWIVEL'; no
- command-line parameters are allowed. (In fact, if you do put any parameters
- on the command line you will get a single-screen summary of SWIVEL's features.
- So typing something like 'SWIVEL HELP' will remind you of the important
- features.) SWIVEL will immediately clear the screen and plot a grid. Grid
- lines in SWIVEL are always plotted in 20-degree increments. The grid is
- plotted in white, and the equator and international dateline are in yellow.
- There is also a yellow box around the normal usable area, from -180 to +180
- degrees longitude, and from -90 to +90 degrees latitude. The limits of the
- screen are somewhat larger when you first start up SWIVEL (-246 to +246
- degrees longitude, and -142 to +142 degrees latitude), so not all of the
- screen is actually used.
- There are currently eight one-letter commands accepted by SWIVEL, and
- I will now describe each in turn:
-
- A - ALL
- This command plots all the data files in the world database. In fact,
- SWIVEL does not know all of the file names; it reads the names from a file
- named ALLFILES.DAT, which is a simple text file that you may modify to
- your liking. It contains one line per file to be plotted, and each line
- starting with a number (the color # to plot the file in) followed by a
- space, followed by the file name. The file ends with the number 0 alone
- on a line. For a list of available color numbers (1-15), just use the
- Color command in SWIVEL or see the beginning of the SWIVEL.PAS source
- listing. The file names can be either absolute (like B:\AF0.MP1) or
- relative (like AFRICA\AF0.MP1). All data files for SWIVEL end in a .MP1
- extension. For colors, I have set the default in ALLFILES.DAT to draw
- all coastlands in red, islands in magenta, lakes in blue, and political
- boundaries in dark grey. Feel free to edit this file to your liking.
- You can abort this command, incidentally, by hitting the Escape key.
- SWIVEL only checks for a keypress after each file is finished plotting,
- so don't expect an immediate response. This command takes a while!
-
- V - VIEW
- This command allows you to specify a single file for viewing. You
- will probably want to use the D command before you use this one, to
- first set a default directory to look in. For example, to view the
- African coastlands, use D to set the directory to 'AFRICA' and then use
- V to specify the name 'AF0'. For the view command, don't add the .MP1
- extension; it's appended automatically by SWIVEL. If you have already
- set a directory name (and you are using the standard SWIVEL directories),
- you will be prompted with the names of all possible files.
- The screen does not clear before each View command, so you can use
- this command to put several files up on the screen at one time.
-
- C - COLOR
- This command sets the color for all subsequent plotting by the V
- command. The default when the program is started is red.
-
- R - RESCALE
- This command allows you to change the area plotted by SWIVEL, to zoom
- in on areas of the globe. You will be informed of the current plotting
- limits, and asked to enter new numbers. You will have to enter four
- numbers (separated only by a space -- no commas!), which are the degrees
- west longitude, south latitude, east longitude, and north latitude.
- Alternatively, you can think of it as Xmin, Ymin, Xmax and Ymax. For
- instance, you could zoom in on the area from -100 to -20 longitude and
- -50 to 0 latitude by typing:
- -100 -50 -20 0
- However, the scale you enter will probably not be the actual scale SWIVEL
- uses. That is because SWIVEL automatically adjusts the scaling to keep
- the true X-Y proportions on the screen. Either the X or Y scaling will
- be adjusted (but never both), in such a way that your intended viewing
- area is always on the screen (and then some).
-
- M - MERCATOR
- By default, SWIVEL does its plotting with a Mercator projection.
- This command toggles the use of Mercator projection; hitting it a first
- time turns off the Mercator projection; hitting it again turns it back
- on, and so on. The screen doesn't clear when this is changed, so you
- can plot the same file twice (in two different colors) to see the
- difference between using Mercator projections and not.
-
- D - DIRECTORY
- This command sets the directory for all subsequent V commands (until
- another D command).
-
- E - ERASE
- This command just erases the Command prompt, so you can print the
- screen without having the text at the top of the printout. Hitting E
- again puts the prompt back up there (although all commands still function
- even when the prompt is gone). Don't ask me how you're going to print
- the screen, however. SWIVEL doesn't provide that capability itself, so
- you'll have to have your own memory-resident screendump command. My
- personal preference is for a utility called Inset, by Inset Systems.
-
- Q - QUIT
- This quits out of SWIVEL.
-
-
-
- Some closing words. First, if you find something wrong with SWIVEL,
- try to fix it yourself. All the source for SWIVEL (as well as an excellent
- multi-windowing graphics package for the EGA) is provided. Sorry, but
- it only compiles under Turbo Pascal 3.01A (and probably earlier versions);
- it doesn't compile under TP 4.0. I'm calling this version 1.0, but I
- really have no intention of enhancing the program since I'm happy with it
- the way it is. But if you find a bug you can't fix, let me know and I'll
- try to track it down.
- I am, however, working a version for the Commodore Amiga (written in
- Aztec C). If you want that, drop me a line for a status report.
-
- ..Ken Van Camp <kvancamp@ARDEC.ARPA>
-
-