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DD & TT ENTERPRISE USA COMPANY

DT ESCORT SYSTEM BOARD B

Processor

80486SX/80486DX/ODP486SX/80486DX2

Processor Speed

16/20/25/33/50(internal)/50/66(internal)MHz

Chip Set

OPTI

Max. Onboard DRAM

32MB

Cache

64KB/256KB

BIOS

AMI

Dimensions

330mm x 218mm

I/O Options

Floppy drive interface, IDE interface parallel port,

Proprietary EISA riser card slot, PS/2 mouse port,

Serial port (2), VGA port, video feature connector

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

PS/2 mouse port

J2

Reset switch

J12A

Serial port (COM 1)

J3

Turbo switch

J12B

Serial port (COM 2)

J4

Turbo LED

J12C

Parallel port

J5

IDE interface LED

J12D

VGA port

J6

Not used

J12E

Floppy drive interface

J9

Speaker

J13A

Video feature connector

J10

Power LED & keylock

J13B

IDE interface

J11

Proprietary EISA riser card slot

S1

USER CONFIGURABLE SETTINGS

Function

Jumper/Switch

Position

»

Floppy drive disabled

E1

Pins 1 & 3 closed

 

Floppy drive enabled

E1

Pins 3 & 5 closed

 

Floppy drive address select 3FO-3F7

E1

Pins 7 & 9 closed

 

Floppy drive address select 370-377

E1

Pins 9 & 11 closed

»

IDE interface disabled

E1

Pins 2 & 4 closed

 

IDE interface enabled

E1

Pins 4 & 6 closed

 

IDE interface address select 3FO-3F7, 1FO-1F7

E1

Pins 8 & 10 closed

 

IDE interface address select 370-377, 170-177

E1

Pins 10 & 12 closed

»

Onboard video enabled

E2

Pins 1 & 2, 3 & 4, 5 & 6 closed

 

Onboard video disabled

E2

Pins 1 & 2, 3 & 4, 5 & 6 open

»

BIOS device select 1MB

E6

Pins 1 & 2 closed

 

BIOS device select 2MB

E6

Pins 3 & 5 closed

 

BIOS device select read only

E6

Pins 2 & 4, 7 & 9, 8 & 10 closed

 

BIOS device select read/write

E6

Pins 4 & 6, 9 & 11, 10 & 12

»

Chipset mode select 2x for 40MHz or less

E7

Pins 3 & 5 closed

 

Chipset mode select 1x for true 50MHz only

E7

Pins 1 & 3 closed

 

Chipset mode RDY1 set for 1X mode

E7

Pins 4 & 6 closed

 

Chipset mode RDY2 set for 2X mode

E7

Pins 2 & 4 closed

»

Chipset mode burst rate select 3-2-2-2

E8

Pins 23 & 24 closed

 

Chipset mode burst rate select 2-1-1-1

E8

Pins 23 & 24 open

»

Chipset mode write states select 0 wait state

E8

Pins 25 & 26 closed

 

Chipset mode write states select 1 wait state

E8

Pins 25 & 26 open

»

Factory configured - do not alter

E9

Pins 39 & 40 closed

»

PS/2 mouse enable at IRQ12

E10

Closed

 

PS/2 mouse disable

E10

Open

»

Factory configured do not alter

E11

Unknown

»

CPU clock select mode 2X

E12

Pins 2 & 3 closed

 

CPU clock select mode 1 x for 486DX 50MHz

E12

Pins 1 & 2 closed

»

Factory configured - do not alter

E15

Pins 1 & 2 closed

Note: If there is no monochrome Hercules card present then the system will automatically assume that address 378h is LPT1 and address 278h is LPT2 pins designated should be in the closed position.

DRAM CONFIGURATION

Size

Bank 0

Bank 1

1MB

(4) 256K x 9

None

2MB

(4) 256K x 9

(4) 256K x 9

4MB

(4) 1M x 9

None

5MB

(4) 256K x 9

(4) 1M x 9

8MB

(4) 4M x 9

None

16MB

(4) 4M x 9

(4) 4M x 9

17MB

(4) 256K x 9

(4) 4M x 9

20MB

(4) 1M x 9

(4) 4M x 9

32MB

(4) 4M x 9

(4) 4M x 9

SRAM CONFIGURATION

Size

Cache

Location

TAG

64KB

(8) 8K x 8

Bank 0 & 1

(1) 8K x 4

256KB

(8) 32K x 8

Bank 0 & 1

(1) 32K x 4

SRAM JUMPER CONFIGURATION

E9

64KB

256KB

Pins 1, 3, 5

Pins 1 & 3 closed

Pins 3 & 5 closed

Pins 2, 4, 6

Pins 2 & 4 closed

Pins 2 & 4 closed

Pins 7, 9, 11

Pins 7 & 9 closed

Pins 9 & 11 closed

Pins 8, 10, 12

Open

Pins 8 & 10 closed

Pins 13, 15, 17

Pins 15 & 17 closed

Pins 15 & 17 closed

Pins 14, 16, 18

Pins 14 & 16 closed

Pins 14 & 16 closed

Pins 19, 21, 23

Pins 21 & 23 closed

Pins 21 & 23 closed

Pins 20, 22, 24

Open

Pins 20 & 22 closed

Pins 26, 28, 30

Pins 26 & 28 closed

Pins 26 & 28 closed

Pins 31, 33, 35

Pins 33 & 35 closed

Pins 33 & 35 closed

Pins 32, 34, 36

Pins 34 & 36 closed

Pins 34 & 36 closed

Pins 37 & 38

Open

Closed

Note: For non-cache configuration pins 25, 26, & 27 should be in the closed position.

NON CACHE CONFIGURATION E16

Pins 1-3-5

Pins 2-4-6

Pins 7-9-11

8 & 10, 11 & 12

Pins 13 & 14

15 & 16, 17 & 18

3 & 5 closed

2 & 4 closed

7 & 9 closed

Closed

Closed

Open

CPU TYPE CONFIGURATION

Jumper

80486DX/80486DX2

80386SX/80486SLC

E8/pins 1, 3, 5

Pins 1 & 3 closed

Pins 3 & 5 closed

E8/pins 2, 4, 6

Pins 2 & 4 closed

Pins 4 & 6 closed

E8/pins 7, 9, 11

Pins 7 & 9 closed

Pins 9 & 11 closed

E8/pins 8, 10, 12

Pins 8 & 10 closed

Pins 10 & 12 closed

E8/pins 13 & 14

Closed

Open

E8/pins 15 & 16

Open

Closed

E8/pins 17 & 18

Closed

Open

E8/pins 19 & 20

Closed

Open

E8/pins 21 & 22

Open

Closed

E13/pins 1 & 2, 3 & 4, 5 & 6

Pins 1 & 2, 3 & 4, 5 & 6 closed

Pins 2 & 3 closed

Note: settings for the 80386SX and 80486SLC are factory configured and should not be altered.

CPU SPEED CONFIGURATION

Speed

U51

U52

Pins 1 & 2

Pins 3 & 4

Pins 5 & 6

Pins 7 & 8

16MHz

Installed

Empty

Closed

Open

Closed

N/A

16MHz

Empty

Installed

Closed

Open

Closed

Closed

20MHz

Installed

Empty

Closed

Open

Open

N/A

20MHz

Empty

Installed

Open

Open

Closed

Closed

25MHz

Installed

Empty

Open

Closed

Closed

N/A

25MHz

Empty

Installed

Closed

Closed

Open

Closed

33MHz

Installed

Empty

Open

Closed

Open

N/A

33MHz

Empty

Installed

Open

Closed

Open

Closed

40MHz

Installed

Empty

Open

Open

Closed

N/A

40MHz

Empty

Installed

Closed

Open

Open

Closed

50MHz

Installed

Empty

Open

Closed

Closed

N/A

50MHz

Empty

Installed

Closed

Closed

Open

Closed

SERIAL PORT A (J3) CONFIGURATION

COM

I/O Address

E4

E5

»

COM1

3F8h

Pins 3 & 5, 2 & 4, 7 & 8

Pins 3 & 5, 2 & 4, 7 & 8

 

COM3

3E8h

Pins 1 & 3, 4 & 6, 7 & 8

Pins 1 & 3, 4 & 6, 7 & 8

 

COM4

2E8h

Pins 3 & 5, 4 & 6, 7 & 8

Pins 3 & 5, 4 & 6

 

Disabled

N/A

Pins 1 & 3, 2 & 4

Pins 1 & 3, 2 & 4

Note: Pins designated should be in the closed position.

SERIAL PORT B (J4) CONFIGURATION

COM

I/O Address

E4

E5

»

COM2

2F8h

Pins 3 & 5, 2 & 4, 7 & 8

Pins 3 & 5, 2 & 4, 7 & 8

 

COM3

3E8h

Pins 1 & 3, 4 & 6, 7 & 8

Pins 1 & 3, 4 & 6, 7 & 8

 

COM4

2E8h

Pins 3 & 5, 4 & 6, 7 & 8

Pins 3 & 5, 4 & 6

 

Disabled

N/A

Pins 1 & 3, 2 & 4

Pins 1 & 3, 2 & 4

Note: Pins designated should be in the closed position.

PARALLEL PORT (J5) CONFIGURATION

COM

IRQ

I/O Address

E3

»

LPT1

IRQ7

3BCh

Pins 3 & 5, 4 & 6, 7 & 8

 

LPT1

IRQ5

3BCh

Pins 3 & 5, 4 & 6, 9 & 10

 

LPT2

IRQ7

378h

Pins 3 & 5, 2 & 6, 7 & 8

 

LPT2

IRQ5

378h

Pins 3 & 5, 2 & 6, 9 & 10

 

LPT3

IRQ7

278h

Pins 1 & 3, 4 & 6, 7 & 8

 

LPT3

IRQ5

278h

Pins 1 & 3, 4 & 6, 9 & 10

 

Disabled

N/A

N/A

Pins 1 & 3, 2 & 4

Note: Pins designated should be in the closed position.

VIDEO MEMORY CONFIGURATION

Size

Bank 0

Bank 1

512KB

(4) 44256

NONE

1024KB

(4) 44256

(4) 44256

Note: Bank 0 is permanently soldered onto the board.