Your recent Tip of the Week about using the Print Screen key to take screen captures was very interesting. I have been attempting to use this method to take screen captures in an old DOS GIS program (Idrisi). The program runs through a full-screen DOS ‘box’ in Windows XP. Pressing the PrtScn key then using ALT-ENTER (to restore to the Windows desktop) I open Paint and attempt to paste. However, nothing is pasted! I have tried using various other combinations of keys such as Shift- Print Screen, but to no avail. Is there a way to take screen captures of this program, other than spending many $100s on purchasing a Windows version of the software?

Unfortunately, when a DOS program is running at full-screen in graphics mode through Windows, Print Screen will not work. If the DOS box is at full-screen and in text mode (for example, when the DOS prompt is displayed) you can use Print Screen and then paste the text into a word processing application (such as Notepad). Assuming that your GIS program uses a graphical interface, then you will not be able to use Print Screen to take screen captures.

However all is not lost! There is a little program called Screen Thief for DOS which can capture programs running within DOS boxes through Windows, in a variety of formats such as BMP (default), TIFF, PCX, or TXT. This utility is freeware and available for download from lists.gpick.net/pages/MS_DOS.htm (you will need to scroll-down the page until you find ‘Screen Thief for DOS’. Be aware there are some tricks I learnt when playing around with this utility, so continue reading!

To install Screen Thief, extract the ZIP archive to a convenient place on your hard drive. For simplicity I suggest ‘C:ST’. Five files will be extracted: ST.EXE, SCANCODE.COM, README.TXT, HISTORY.TXT, and CONFIG.ST. At the moment you don’t need to worry about any files except ST.EXE. However, I strongly encourage you to read the README.TXT file at a later time, so you can find out about the more advanced features of Screen Thief. Open a DOS command prompt, by going to the ‘Start’ menu > ‘Run’ and type ‘cmd’ (without the quotes) and click OK. Change to the directory containing Screen Thief and start the program (ST.EXE), for example:
cd C:ST [ENTER Key]
ST [ENTER Key]
A blue screen should appear with all the configuration information. Screen Thief is now running in the background (you can see at the top of the DOS box it reads ‘C:WindowsSystem32cmd.exe - st’). You will now need to start your GIS program from within that DOS box. This is because each DOS box opened is treated as a separate DOS ‘virtual machine’. Screen Thief is running in the DOS box we have currently open, but if you opened another box it will not be running. So, in our DOS box running Screen Thief, you will need to change to the directory containing the GIS program then start it with the appropriate command. Be aware that because Screen Thief is running in the background, the DOS box will not recognise long file names (i.e. file names longer than 8 characters). So, all your directories and files longer than 8 characters will be truncated. For example: ‘C:Program Files’ becomes ‘C:Progra~1′. In case you are wondering, the ~1 is necessary because some files/directories have the same first 6 characters. For example, a system which has the directories Microsoft Office, Microsoft Money and Microsoft Games will be abbreviated: Micros~1, Micros~2 and Micros~3.

Once you have started the GIS program, don’t worry if it goes to full-screen mode, Screen Thief is still running quietly in the background. To take a screen capture, press the CTRL-ALT-T key combination. Your PC speaker should make a short beep to indicate the capture has been taken. The image file is stored in the currently active directory. So, this will be the directory of the GIS program (you can change where the captures are stored by following the instructions in the README.TXT file).