640KB TURBO SYSTEM Motherboard Settings and Configuration

Processor

8088

Processor Speed

4.77/8MHz

Chip Set

None

Max. onboard DRAM

640KB

SRAM Cache

None

BIOS

Phoenix

Dimensions

330mm x 218mm

I/O Options

None

NPU Options

8087

CONNECTIONS

Purpose

Location

Purpose

Location

Keylock

C1

Speaker

C4

Power LED

C2

Reset switch

C5

Turbo LED

C3

USER CONFIGURABLE SETTINGS

Function

Jumper/Switch

Position

»

CPU speed select low switchable via keyboard

J1

pins 1 & 2 closed

CPU speed select high switchable via keyboard

J1

pins 3 & 4 closed

CPU speed select normal/turbo switchable via keyboard

J1

pins 5 & 6 closed

»

Factory configured - do not alter

SW1/switch 1

Off

»

NPU disabled

SW1/switch 2

On

NPU enabled

SW1/switch 2

Off

»

Factory configured - do not alter

SW1/switch 3

Off

»

Factory configured - do not alter

SW1/switch 4

Off

Note: The board can only use the normal/turbo mode with a reprogrammed BIOS, this option may not be available on all boards.

DRAM CONFIGURATION

Size

Bank 0

Bank 1

Bank 2

Bank 3

256KB

(8) 41256

NONE

NONE

NONE

512KB

(8) 41256

(8) 41256

NONE

NONE

578KB

(8) 41256

(8) 41256

(8) 4164KB

NONE

640KB

(8) 41256

(8) 41256

(8) 4164KB

(8) 4164KB

EPROM/ROM CONFIGURATION

Switch

2764 (U25A)

27128 (U25B)

8K ROM (U25A)

32K ROM (U25C)

SW2/1

On

On

On

Off

SW2/2

Off

Off

Off

On

SW2/3

On

Off

On

Off

SW2/4

Off

On

Off

On

SW2/5

On

On

Off

On

SW2/6

Off

Off

On

Off

SW2/7

On

On

Off

On

SW2/8

Off

Off

On

Off

SW3/1

Off

On

Off

On

SW3/2

On

Off

On

Off

SW3/3

Off

Off

Off

On

SW3/4

On

On

On

Off

DISPLAY CONFIGURATION

Display Adapter

SW1/5

SW1/6

SW1/7

SW1/8

None

On

Off

N/A

N/A

Color/Graphics (40x20)

Off

On

On

On

Color/Graphics (80x25)

On

Off

On

On

Monochrome or Both

Off

Off

On

On

FLOPPY DRIVE CONFIGURATION

Drives Installed

SW1/7

SW1/8

1

On

On

2

Off

On

3

On

Off

4

Off

Off