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Technical Articles
Running DataEase for DOS 4.53 on Windows XP
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David A. Gray, MBA
Chief Wizard, WizardWrx
I have clients running DataEase 4.53 on Windows XP, and our client billing application is still
DataEase 4.53, albeit on a Novell network.
You need a PIF (shortcut file to a MS-DOS program) to gain control of the NTVDM settings that are
critical to running DataEase on Windows XP. Mine has the following settings:
- Memory Tab:
- Total: Auto
- Initial Environment: Auto
- Expanded (EMS) Memory Total: None
- Extended (XMS) Memory Total: 4096
- Uses HMA: Checked
- MS-DOS Protected-mode (DPMI) Memory Total: 4096
Figure 1 - Memory Tab of DataEaee PIF.
- Screen Tab:
- Usage: Window (This is up to you.)
- Window: Restore Settings at Start-up: Checked
- Performance: Fast ROM Emulation: Checked
- Dynamic Memory Allocation: Checked
Figure 2 - Screen Tab of DataEaee PIF.
- Misc. Tab
- Allow Screen Saver: Checked
- Background: Always Suspend: Unchecked
- Termination: Warn if still active: Checked
- Idle Sensitivity: Slider to far right
- Other: Fast Pasting: Checked
- Window Shortcut Keys: All checked
Figure 3 - Misc. Tab of DataEaee PIF.
Notes
- The Idle Sensitivity setting on the Miscellaneous tab is extremely important, as it has a significant effect on performance. The default setting, which is at the other end of the slider, produces very poor performance.
- EMS memory is of almost no value in recent versions of DataEase. XMS and DPMI memory are essential.
- I set upper bounds of 4096 KB on both XMS and DPMI memory because DataEase can't really use more than that, and automatic allocation adversely affects performance.
Creating Your PIF
In order to create a PIF, you must create a shortcut to a MS-DOS program such as DataEase itself. When you view the shortcut, the three extra tabs discussed above will appear, as shown in Figure 4 below.
Figure 4 - General Tab of DataEaee PIF, showing additional Memory, Screen, and Misc. tabs.
Once the PIF exists, the Program tab can be altered, as shown in Figure 5 below.
Figure 5 - Program Tab of DataEaee PIF, showing subsequent addition of command line arguments.
Limiting Users to One Instance
A common problem with many applications, including DataEase, is that Windows will let you start two or more copies. While this is not usually a problem, for DataEase users, the consequences can be quite serious, including corruption of the data base.
This problem led us to create P6_Just_1, a Windows program that you add to your Start Menu in place of the DataEase PIF discussed above. While you still need the PIF, P6_Just_1 will see to it that only one copy is running. Here is how it works.
- Using information supplied by you in the shortcut, it looks for another instance of the program that you want to call.
- If another instance is found, its main window is brought to the foreground and given the focus.
- If another instance is not found, the program is started and given the focus.
Read more about P6Just1 and download your free trial copy to protect your data from corruption.
