When a block oriented protocol like IBM's 3780 is running in a DOS window under Windows 95/98, it is important that the operating system doesn't try and swap you out to run another program such as Screen Saver.  To solve this problem try the following:

1. Right Click the Icon that your bi-sync program is operating under [e.g., the DOS Icon];

2. Click "Properties"

3. Select the "Misc" tab

4. Uncheck the "Allow Screen Saver" box

5. Move the "Idle Sensitivity" to the "LOW" end of the scale

6. Click "Apply" and then "OK."