DTK COMPUTER, INC.

RS-232 DUAL I/O SHORT CARD

Card Type

Serial card

Chip Set

Unidentified

Maximum Onboard Memory

Unidentified

I/O Options

Serial ports (2)

Data Bus

8-bit ISA

CONNECTIONS

Function

Label

Function

Label

Serial port 1

J1

Serial port 2

J2

SERIAL PORT 1 ADDRESS SELECTION

Setting

S1/1

S1/2

S1/3

S1/4

S1/5

COM1 (3F8h)

On

Off

Off

Off

On

COM2 (3E8h)

Off

Off

Off

Off

Off

COM3

Off

Off

On

On

Off

SERIAL PORT 1 ADDRESS SELECTION (CONTINUED)

Setting

S1/6

S1/7

S1/8

S1/9

S1/10

COM1 (3F8h)

Off

Off

Off

Off

Off

COM2 (3E8h)

On

Off

Off

On

Off

COM3

Off

Off

Off

Off

Off

Note: In order to use COM3, you must program COM3 into your software. Switches 5 & 6, 7 & 8 specify the IRQ selection. See tables below for specific information.

SERIAL PORT 2 ADDRESS SELECTION

Setting

S1/1

S1/2

S1/3

S1/4

S1/5

COM1 (2F8h)

Off

Off

Off

Off

Off

COM2 (2E8h)

On

On

Off

Off

On

COM4

Off

Off

On

On

Off

SERIAL PORT 2 ADDRESS SELECTION (CON’T)

Setting

S1/6

S1/7

S1/8

S1/9

S1/10

 

COM1 (2F8h)

On

On

Off

On

On

»

COM2 (2E8h)

Off

Off

On

Off

Off

 

COM4

Off

Off

Off

Off

Off

Note: In order to use COM4, you must program COM4 into your software.

SERIAL PORT 1 INTERRUPT SELECTION

IRQ

COM

S1/5

S1/6

IRQ3

COM2

Off

On

IRQ4

COM1

On

Off

SERIAL PORT 2 INTERRUPT SELECTION

IRQ

COM

S1/7

S1/8

IRQ3

COM2

Off

On

IRQ4

COM1

On

Off

MISCELLANEOUS TECHNICAL NOTES

If your system already has a serial port then you will use the settings for serial port 1. This will enable only one port in the RS-232 board. If your system does not have any aerial ports, you will have to use the settings for serial port 2. This will enable both ports on the RS-232 board. To use the ports as COM3 and COM4, you will need to write software to support this function. Switch settings are provided.