J-MARK COMPUTER CORPORATION

J-656B

Processor

Pentium

Processor Speed

75/90/100/120/133/150/180/200MHz

Chip Set

Intel

Video Chip Set

None

Maximum Onboard Memory

128MB (EDO supported)

Maximum Video Memory

None

Cache

256/512KB

BIOS

Award

Dimensions

330mm x 218mm

I/O Options

32-bit PCI slots (4), floppy drive interface, IDE interfaces (2), parallel port, PS/2 mouse interface, serial ports (2), VRM connector. IR connector

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

Serial port 2

CN1

Speaker

J4

Serial port 1

CN2

Power LED & keylock

J5

Parallel port

CN3

Turbo LED

J6

Floppy drive interface

CN4

Turbo switch

J7

IDE interface 2

CN5

IR connector

JP8

IDE interface 1

CN6

PS/2 mouse interface

MS1

Reset switch

J2

32-bit PCI slots

PC1 – PC4

IDE interface LED

J3

VRM connector

VRM

USER CONFIGURABLE SETTINGS

Function

Label

Position

»

Factory configured - do not alter

J8

Unidentified

»

Factory configured - do not alter

J9

Unidentified

»

PCI CLK select CLK/4

JP3

Pins 2 & 3 closed

 

PCI CLK select CLK/3

JP3

Pins 1 & 2 closed

»

I/O address select 250 HEX

JP4

Pins 2 & 3 closed

 

I/O address select 3F0 HEX

JP4

Pins 1 & 2 closed

»

IDE interface 1 IRQ select IRQ14

JP5

Pins 1 & 2 closed

 

IDE interface 1 IRQ select MIRQ1

JP5

Pins 2 & 3 closed

»

IDE interface 2 IRQ select IRQ15

JP6

Pins 1 & 2 closed

 

IDE interface 2 IRQ select MIRQ0

JP6

Pins 2 & 3 closed

»

Factory configured - do not alter

JP9

Unidentified

»

Green PC disabled

JP10

Open

 

Green PC enabled

JP10

Closed

»

Factory configured - do not alter

JP13

Unidentified

»

Factory configured - do not alter

JP15

Unidentified

»

Factory configured - do not alter

JP16

Unidentified

»

CMOS memory normal operation

JP17

Open

 

CMOS memory clear

JP17

Closed

»

CPU type select write back

JP18

Open

 

CPU type select write through

JP18

Closed

»

CPU pipeline enabled

JP19

Closed

 

CPU pipeline disabled

JP19

Open

»

Factory configured - do not alter

JP20

Unidentified

»

Factory configured - do not alter

JP24

Unidentified

»

Factory configured - do not alter

JP32

Unidentified

DRAM CONFIGURATION

Size

Bank 0

Bank 1

8MB

(2) 1M x 36

None

16MB

(2) 2M x 36

None

16MB

(2) 1M x 36

(2) 1M x 36

24MB

(2) 2M x 36

(2) 1M x 36

DRAM CONFIGURATION (CON’T)

Size

Bank 0

Bank 1

32MB

(2) 4M x 36

None

32MB

(2) 2M x 36

(2) 2M x 36

40MB

(2) 4M x 36

(2) 1M x 36

48MB

(2) 4M x 36

(2) 2M x 36

64MB

(2) 8M x 36

None

64MB

(2) 4M x 36

(2) 4M x 36

72MB

(2) 8M x 36

(2) 1M x 36

80MB

(2) 8M x 36

(2) 2M x 36

96MB

(2) 8M x 36

(2) 4M x 36

128MB

(2) 8M x 36

(2) 8M x 36

Note: Board accepts EDO memory. Board also accepts x 32 SIMMs. Banks are interchangeable.

CACHE CONFIGURATION

Size

Bank 0

Bank 1

TAG

256KB (A)

(2) 32K x 32

None

(1) 8K x 8

256KB (B)

None

(8) 32K x 8

(1) 8K x 8

512KB (A)

(2) 64K x 32

None

(1) 16K/32K x 8

512KB (B)

None

(8) 64K x 8

(1) 16K/32K x 8

CACHE JUMPER CONFIGURATION

Size

JP14

256KB (A)

Pins 1 & 2 closed

256KB (B)

Pins 1 & 2 closed

512KB (A)

Pins 2 & 3 closed

512KB (B)

Pins 2 & 3 closed

CACHE VOLTAGE CONFIGURATION

Voltage

JP1

JP2

3v synchronous

Open

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

3v asynchronous

Open

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

5v mixed asynchronous

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

Open

CPU SPEED SELECTION

CPU speed

Clock speed

Multiplier

JP11

JP12

JP26

JP27

75MHz

50MHz

1.5x

Open

Open

Open

Open

90MHz

60MHz

1.5x

Open

Closed

Open

Open

100MHz

66MHz

1.5x

Closed

Closed

Open

Open

120MHz

60MHz

2x

Open

Closed

Open

Closed

133MHz

66MHz

2x

Closed

Closed

Open

Closed

150MHz

60MHz

2.5x

Open

Closed

Closed

Closed

180MHz

60MHz

3x

Open

Closed

Closed

Open

200MHz

66MHz

3x

Closed

Closed

Closed

Open

CPU VOLTAGE SELECTION

Voltage

JP28

JP29

JP30

3.3v

Closed

Open

Open

3.45v

Open

Closed

Open

3.6v

Open

Open

Closed

BIOS SELECTION

Setting

JP21

JP31

 

EPROM

Pins 1 & 2 closed

Pins 2 & 3 closed

»

12v flash

Pins 2 & 3 closed

Pins 1 & 2 closed

 

5v flash

Pins 2 & 3 closed

Pins 2 & 3 closed