Browse Prior Art Database

DOS Dynamic Device Driver

IP.com Disclosure Number: IPCOM000060738D
Original Publication Date: 1986-May-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Crossley, JF: AUTHOR

Abstract

This technique involves the addition or removal of device drivers from the base portion of an operating system, after the system has been initialized, which does not offer this facility to the user. In particular, it applies to the IBM Personal Computer and the operating system DOS (Disk Operating System release 2.0 or above). The user specifies to the system, via the CONFIG.SYS file, a dummy device driver which is used merely as a place holder. Device drivers in the system are chained to one another by the operating system during the systems IPL, BOOT, or initialization operation. After the system has been started and is available for normal application programs to begin processing, the dynamic device driver concept is employed.

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DOS Dynamic Device Driver

This technique involves the addition or removal of device drivers from the base portion of an operating system, after the system has been initialized, which does not offer this facility to the user. In particular, it applies to the IBM Personal Computer and the operating system DOS (Disk Operating System release 2.0 or above). The user specifies to the system, via the CONFIG.SYS file, a dummy device driver which is used merely as a place holder. Device drivers in the system are chained to one another by the operating system during the systems IPL, BOOT, or initialization operation. After the system has been started and is available for normal application programs to begin processing, the dynamic device driver concept is employed. To add a new device driver to the operating system, an application program is started to do the following: 1. Locate the dummy place holder device driver. 2. Break the link list of device drivers after the dummy place holder device driver (via the device driver header). 3. Tie the new user device driver into the broken link list after the place holder device driver. 4. Re-establish the link list chain with the additional user or system device driver. 5. Call the new device driver to perform its initialization (simulation of the normal system initialization). 6. The application program must terminate execution and keep the added device driver resident in storage. To remove a dynamic device driver, the user must r...