Specifications

Theory of Operation

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Power Requirements

In most applications, the EPC-33/34 operates on 5V DC power only. The voltage

required is between 4.75 and 5.25 volts. +12V must be supplied via the ISA-bus or

the power connector to erase or program the FLASH devices, including the BIOS.

+5V may be supplied either via the ISA-bus edge connector, the PC/104 bus header,

or the power connector. Care must be taken that the maximum current ratings of the

connectors are not exceeded.

Peripheral Interfaces

Serial and parallel port functions and a floppy disk drive controller are contained in

a multi-IO chip, the FDC37C665GT, manufactured by Standard Microsystems Corp.

(SMC). For details of the operation of these functions, refer to the SMC data sheet

for this device.

Serial Ports

The COM1 serial port is located in a user-definable I/O address range. The default

is 3F8. The default is for COM1 serial port interrupts to be signaled using IRQ4.

Connection to COM1 is provided by a standard male DB-9 connector mounted on

the card bracket.

The COM2 serial port is located in a user-definable I/O address range. The default

is 2F8. The default is for COM2 serial port interrupts to be signaled using IRQ3.

Connection to COM2 is made via a standard header connector on the board that is

shared with the parallel port.

Both COM ports are 16C550-compatible and contain FIFOs. The best way to bring

up the FIFO is to set it up within the applications software, but if that is not possible

it can be set through the debug (or equivalent) routine. Bit 0 of the FIFO Control

(IIR). For example, if COM1 uses the default address 3F8, writing to 3FA with the

hex value 01 enables the FIFO.