HP LTE Notebook PC 5250 LTE 5000 Family of Personal Computers Maintenance and - Page 25

drive can be used simultaneously. The audio subsystem is integrated into the system board. The system supports an internal microphone, stereo speakers, SoundBlaster PRO compatible audio, CD-ROM audio inputs, an external jack for headphones or speakers, microphone jack, and line-input jack. Line and CD-ROM inputs and the speaker outputs are passed through the external options connector and supported by both expansion bases. The internal speakers are disabled when the computer is docked in the expansion base and when headphones or external speakers are installed. The heart of the audio subsystem is the ESS1688 (ESS688 on Windows 3.1/Dos 6 units) AudioDrive ASIC that provides 16-bit stereo WAV audio, audio mixing, and FM music synthesis. The entire audio system connects directly to the ISA bus. The ESS1688 is OPL3 compatible and compatible with SoundBlaster PRO and Microsoft Windows Sound System. It can record, compress, and play back sound and music at 8 or 16 bits up to 44 Khz. The computer has one PC Card (PCMCIA) controller that supports a Type III PC card slot that supports either two Type II PC Cards or one Type III PC Card. A PC card door prevents contamination of the slot. The controller is Intel ExCA compatible and complies with the Berlin revision of the PCMCIA standard. The controller supports 5-V cards and all current Compaq PC Cards. A second PC Card controller is located in both expansion bases. The diskette drive controller supports 720K, 1.2 MB, and 1.44 MB densities as well as automatic media detection. Diskette drives can be used in the computer MultiBay and the expansion bases. When using Windows 95, real mode drivers must be used for a diskette drive in the expansion base. For more information see "Solving Diskette and Diskette Drive Problems" in Chapter 2. The PC87334 Super I/O contains two UARTs which are fully compatible with NS15450 and NS16550. Both ports support MIDI baud rates and one port also supports IrDA and HP SIR compliant signaling protocol. The two serial ports are configured as one RS- 232C serial port and one infrared (IrDA) port. o The standard RS-232 serial port has an 82550 compatible serial controller. The physical connector is a standard 9-pin D connector. The interface can be configured as COM1, COM2, COM3, or COM4. o The infrared communication is implemented with an 82550 compatible serial controller. The minimum data rate supported by the Infrared Port is 115K bits per seconds. The interface can be configured as COM1, COM2, COM3, or COM4. The parallel port support is integrated into the PC87334 Super I/O. The computer has one parallel port that can be configured to operate in compatible mode, enhanced modes 1.7 and 1.9 (EPP), and extended capabilities (ECP) mode (IEEE-1284 compatible). The default mode is the compatible mode. The physical connector is a standard 25-pin D connector. The parallel port interface can be configured as LPT1, LPT2, or LPT3. When the computer is mounted in either expansion base, the system can