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External Serial Ports
A National Semiconductor PC87336 chip is used to implement the two standard PC COM ports. These COM ports are compatible with the standard 16450 and 16550 architectures. They are labeled COM A and COM B and may be configured for any of the following ports:
•COM1 (I/O address =
•COM2 (I/O address =
•COM3 (I/O address =
•COM4 (I/O address =
The serial ports cannot share the interrupts with other devices. The COM3 and COM4 I/O addresses are used for the touch screen controller, but a different IRQ is used.
Printer Port
A National Semiconductor PC87336 implements a standard PC parallel printer port. The port meets the IEEE 1284 specification and supports ECP and EPP modes.
Floppy Disk Drive Port
The National Semiconductor PC87336 implements a PC floppy disk port which will support one floppy disk drive. The port includes +12 V and +5 V to power the disk drive, which will be cur- rent limited by Raychem Polyfuses to 1 A max. The connector for this port is unique to the Clean Screen, so a Planar supplied drive with custom cables should be used. Only
Sound Blaster Compatible Sound System
Sound Blaster™ compatible sound is provided by an ESS ES1688 sound controller using
Optional Resistive Touch Screen Controller
Optional touch screen support is provided by an ELO TouchSystems
Thermostatic Switch/Temperature Sensor
An Analog Devices AD22105 thermostatic switch supports the temperature sensor circuit on the main board to allow the system to be shut down in an over temperature condition. The switch is used to detect when the internal ambient air exceeds approximately 50°C (±3°C). When the tem- perature exceeds 50°C the BIOS will place the Pentium™ processor in a Standby mode. The Over Temperature Error fault can only be cleared by entering the BIOS Setup during
32Planar Clean Screen PC User’s Manual