Techniques for supporting operating systems for portable computers

• US 5,454,110 A
• Filed: 08/26/1994
• Issued: 09/26/1995
• Est. Priority Date: 04/15/1992
• Status: Expired due to Term

• Current Assignee: Lenovo Singapore Pte Limited (Lenovo Group Ltd.)
• Original Assignee: International Business Machines Corporation
• Inventors: Kannan, Krishnamurthl, Lybrand, David P., Novak, Frank P.
• Primary Examiner(s): Kriess, Kevin A.
• Assistant Examiner(s): CHAVIS, JOHN Q
• Application Number:
  US08/294,824
• Time in Patent Office: 396 Days
• Field of Search: 395/650, 395/700, 395/375
• US Class Current: 713/2
• CPC Class Codes: G06F 9/4406 Loading of operating system

Abstract

This invention describes a set of methods and techniques that together address the deficiencies of the basic input/output system (BIOS) and the advanced basic input/output system (ABIOS) in the context of a pen-based portable computer while retaining much of its strengths in terms of providing an insulating layer between the hardware and the operating system such that the same operating system code body will execute in a variety of hardware platforms. In particular, the following deficiencies have been addressed. (a) A dual boot capability allowing the user to select, through a set-up procedure, either a conventional (DOS-style) booting procedure or a Penpoint-style booting procedure. (b) The capability to mast certain device characteristics from the operating system, defined as a callback mechanism. (c) A method for collecting and maintaining device state information of a device that could be disconnected or reconnected during the operating of the computer.

Claims

1. A system for detecting when a device has been attached to or detached from a computer without affecting the usability of the computer, comprising:

an operating system, said operating system configured to control the operations of the computer, said operating system having requesting means for requesting the performance of a device checking function;

operating system support means, configured to accept and transmit information to and from said operating system, said operating system support means comprising,

sending means for sending a stimulus to the device; and

transferring means for transferring control to the operating system;

said operating system support means is configured to wait a predetermined amount of time for a response of the device, said response representing the presence or absence of the device;

processing means for processing a staging event, said processing means determining if said staging event is due to an input from the device or from the expiration of said predetermined amount of time; and

stimulating means for stimulating the device a predetermined number of times if said staging event is due to the expiration of said predetermined amount of time, and indicating the absence of the device if the device does not respond to said stimulation; and

interpreting means for interpreting the input from the device and processing that input accordingly when said staging event is due to an input from the device;

wherein said operating system support means transfers control to the operating system when the operations corresponding to said staging event are completed.

2. The system of claim 1, wherein said interpreting means further comprises means for determining whether said input from the device is a response to said stimulus.

3. The system of claim 1, wherein said interpreting means further comprises means for determining whether said input from the device is an input indicative of the attachment of the device.

4. The system of claim 1, wherein said interpreting means further comprises means for determining whether said input from the device is information resulting from the operation of the device.

5. The system of claim 1, wherein said response of the device may be manifested as a staging event.

6. A method for detecting when a device has been attached to or detached from a computer without affecting the usability of the computer, comprising the steps of:

(1) requesting the performance of a device checking function by the computer operating system;

(2) sending a stimulus to the device;

(3) transferring control to the computer operating system;

(4) waiting a predetermined amount of time for a staging event to occur, said staging event representing presence or absence of the device; and

(5) processing said staging event comprising the steps of;

(a) determining if said staging event is due to an input from the device or from the expiration of said predetermined amount of time,

(b) stimulating the device a predetermined number of times if said staging event is due to the expiration of said predetermined amount of time, and indicating the absence of the device if the device does not respond to said stimulation,

(c) interpreting the input from the device and processing that input accordingly when said staging event is due to an input from the device; and

(d) transferring control to the operating system.

7. The method of claim 6, wherein said interpreting step further comprises the step of determining whether said input from the device is a response to said stimulus.

8. The method of claim 6, wherein said interpreting step further comprises the step of determining whether said input from the device is an input indicative of the attachment of the device.

9. The method of claim 6, wherein said interpreting step further comprises the step of determining whether said input from the device is information resulting from the operation of the device.