Specifications

EPC-8A Hardware Reference

Table A-12. Coprocessor Interface: For the EPC-8A DX, DX replaces the 80287 of PC⁄AT

I/O Addr Functional group Usage

0F0 Coprocessor Clear coprocessor busy

0F1 Reset coprocessor

Table A-13. EXM Configuration

I/O Addr Functional group Usage

100 EXM Configuration EXM IDs (on each EXM module)

102 EXM option byte 1 (slot-specific)

103 EXM option byte 2 (slot-specific)

Table A-14. Ethernet

I/O Addr Functional group Usage

240–25F Default Ethernet registers

(programmable)

Table A-15. Serial I/O (Com2) Port: National Semiconductor PC87336

emulating 8251 of PC⁄AT

I/O Addr Functional group Usage

2F8 COM2 serial port Receiver/transmitter buffer

Baud rate divisor latch (LSB)

2F9 Interrupt enable register

Baud rate divisor latch (MSB)

2FA Interrupt ID register

2FB Line control register

2FC Modem control register

2FD Line status register

2FE Modem status register

Table A-16. Parallel I/O (LPT1) Port: National Semiconductor PC87336

emulating 8255 of PC⁄AT

I/O Addr Functional group Usage

378 LPT1 parallel port Printer data register

379 Printer status register

37A Printer control register

Table A-17. VGA

I/O Addr Functional group Usage

3B4 VGA CRT Controller index

3B5 CRT Controller data

3BA Feature control output, Input status

3C0 Attribute controller Index/Data

3C1 Attribute controller Index/Data