MECER CORPORATION

B860/B860 (REV. A)

Processor

CX486SX/80486SX/80486DX/80486DX2/Pentium Overdrive

Processor Speed

25/33/40/50(internal)/50/66(internal)MHz

Chip Set

Unidentified

Max. Onboard DRAM

32/128MB (depends on board revision)

Cache

128/256KB

BIOS

AMI

Dimensions

330mm x 218mm

I/O Options

32-bit VESA local bus slots (2)

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

Power LED & keylock

JP6 pins 1 - 5

Reset switch

JP6 pins 19 - 20

Speaker

JP6 pins 6 - 9

External battery

JP17

Turbo LED

JP6 pins 11 - 12

Auxiliary keyboard connector

JP35

Turbo switch

JP6 pins 16 - 17

32-bit VESA local bus slots

SL1 & SL2

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

PQFP CPU disabled

JP1

Closed

 

PQFP CPU enabled

JP1

Open

»

CMOS memory normal operation

JP16

pins 1 & 2 closed

 

CMOS memory clear

JP16

pins 2 & 3 closed

»

Battery type select 4.5v

JP34

Closed

 

Battery type select 6.0v

JP34

Open

»

CPU speed select 20/25MHz

JP72

Closed

 

CPU speed select => 33MHz

JP72

Open

»

VESA card select normal

JP89

Closed

 

VESA card select Weitek VESA card only

JP89

Open

DRAM CONFIGURATION (REV. 0)

Size

Bank 0

Bank 1

2MB

(4) 256K x 9

(4) 256K x 9

5MB

(4) 256K x 9

(4) 1M x 9

8MB

(4) 1M x 9

(4) 1M 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

DRAM CONFIGURATION (REV. A)

Size

Bank 0

Bank 1

2MB

(4) 256K x 9

(4) 256K x 9

5MB

(4) 256K x 9

(4) 1M x 9

8MB

(4) 1M x 9

(4) 1M 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

65MB

(4) 256K x 9

(4) 16M x 9

68MB

(4) 1M x 9

(4) 16M x 9

80MB

(4) 4M x 9

(4) 16M x 9

128MB

(4) 16M x 9

(4) 16M x 9

DRAM JUMPER CONFIGURATION

Revision

JP76

JP77

JP90

JP91

JP92

JP93

Rev. 0

1 & 2

2 & 3

Open

Open

Open

2 & 3

Rev. A

2 & 3

1 & 2

Closed

Closed

Closed

1 & 2, 3 & 4

Note: Pins designated should be in the closed position.

CACHE CONFIGURATION

Size

Bank 0

Bank 1

TAG

128KB

(4) 32K x 8

NONE

(1) 8K x 8

256KB

(4) 32K x 8

(4) 32K x 8

(1) 32K x 8

CACHE JUMPER CONFIGURATION

Size

JP7

JP8

128KB

pins 1 & 2 closed

pins 2 & 3 closed

256KB

pins 1 & 2 closed

pins 1 & 2 closed

CPU TYPE CONFIGURATION

Type

JP2

JP3

JP4

JP5

JP9

CX486SX

2 & 3

Open

Open

2 & 4

2 & 3

80486SX (PQFP)

Open

Open

Open

3 & 5

2 & 3

80486SX (PGA)

2 & 3

Open

Open

2 & 3

2 & 3

80486DX

1 & 2, 3 & 4

2 & 3

Open

2 & 3

2 & 3

80486DX2

1 & 2, 3 & 4

2 & 3

Open

2 & 3

2 & 3

Pentium Overdrive

1 & 2, 3 & 4

1 & 2

Closed

2 & 3

2 & 3

Note: Pins designated should be in the closed position.

CPU SPEED CONFIGURATION

Speed

JP33

JP36

25MHz

pins 2 & 3 closed

pins 2 & 6, 4 & 8 closed

33MHz

pins 2 & 3 closed

pins 3 & 7, 4 & 8 closed

40MHz

pins 2 & 3 closed

pins 2 & 6 closed

50iMHz

pins 2 & 3 closed

pins 2 & 6, 4 & 8 closed

50MHz

pins 1 & 2 closed

pins 3 & 7 closed

66iMHz

pins 2 & 3 closed

pins 3 & 7, 4 & 8 closed

VESA WAIT STATE CONFIGURATION

Wait states

ID2

0 wait states

Open

1 wait state

Closed

BUS SPEED CONFIGURATION

CPU speed

ID3

<= 33MHz

Open

> 33MHz

Closed

PAL JUMPER CONFIGURATION

Revision

JP96

TP1

TP2

TP3

TP4

Rev. 0

Open

2 & 3

2 & 3

2 & 3

2 & 3

Rev. A

Closed

1 & 2

1 & 2

1 & 2

1 & 2

Note: Pins designated should be in the closed position.

BOARD REVISION JUMPER CONFIGURATION

Revision

JP78

JP79

JP97

JP98

Rev. 0

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

Rev. A

pins 2 & 3 closed

pins 2 & 3 closed

pins 2 & 3 closed

pins 2 & 3 closed

Note: These jumpers configure the board revision.