Use of Multiple Communications Methods
Original Publication Date: 1989-Apr-01
Included in the Prior Art Database: 2005-Jan-27
When a DOS extension that supports multiple communications programs is loaded, all interrupt vectors that support communications interfaces are tested for a "signature" that identifies each communication program. The search order is part of the DOS extension but may be overridden through the use of a parameter specified when loading the DOS extension. By saving information that indicates the communication program type, the specifics of using that communication program can be accommodated. This also allows multiple communications programs to be used simultaneously. (Image Omitted) Thus, when the user's application calls the DOS extension to do communications, the software being used to do the actual operation is hidden from the user and all communication methods look the same to the application program.