Patent ID: 6226237
Filing Date: 2001-05-01
Classification: G06F,Y02D

Abstract:
A digital computer comprising both a computer subsystem and a CD-ROM subsystem:said computer subsystem including a digital computer bus via which commands and data are exchanged between various pairs of digital computer devices of the computer subsystem that are selected from a group consisting of a central processing unit (""CPU""), a random access memory (""RAM""), a display, a read-write mass storage device, a manual input device, and a digital-audio generating integrated circuit (""IC""); andsaid CD-ROM subsystem including:a CD-ROM drive;an audio output amplifier that is coupled to the CD-ROM drive for receiving an analog audio signal from the CD-ROM drive;a plurality of CD-ROM control buttons for controlling operation of the CD-ROM drive during replay of audio compact disks (""CDs""); andan audio-interface IC that is continuously connected to the digital computer bus of said computer subsystem, to a bus extension included in said CD-ROM subsystem to which the CD-ROM drive connects, and to the CD-ROM control buttons, said audio-interface IC comprising transmission gates to selectively couple or isolate said digital computer bus and said bus extension;the audio-interface IC when the CD-ROM subsystem is energized:in a first operating mode in which the computer subsystem is energized and operating, relaying commands and data between the digital computer bus of the computer subsystem and the CD-ROM drive; andin a second operating mode in which the computer subsystem is not energized and is inoperative, autonomously responding to signals received from the CD-ROM control buttons and transmitting commands to the CD-ROM drive, the commands causing the CD-ROM drive to play an audio CD present in the CD-ROM drive.