UNIDENTIFIED

TURBO MAINBOARD (4.77/10MHZ)

Processor

8088

Processor Speed

4.77/10MHz

Chip Set

Unidentified

Video Chip Set

None

Maximum Onboard Memory

640KB

Maximum Video Memory

None

Cache

None

BIOS

Unidentified

Dimensions

276mm x 196mm

I/O Options

None

NPU Options

8087

CONNECTIONS

Purpose

Location

Purpose

Location

Speaker

JP1

Turbo LED

JP5 pins 1 & 2

Keylock

JP3

Power LED

JP5 pins 3 & 4

Reset switch

JP4

Turbo switch

JP6

USER CONFIGURABLE SETTINGS

Function

Label

Position

»

Factory configured - do not alter

SW1/1

Off

»

NPU not installed

SW1/2

On

 

NPU installed

SW1/2

Off

»

Factory configured - do not alter

SW1/3

Off

»

Factory configured - do not alter

SW1/4

Off

DRAM CONFIGURATION

Size

Bank 0

Bank 1

Bank 2

Bank 2A

Bank 3

Bank 3A

256KB

(9) 41256

None

None

None

None

None

512KB

(9) 41256

(9) 41256

None

None

None

None

576KB

(9) 41256

(9) 41256

(2) 4464

(1) 4164

None

None

640KB

(9) 41256

(9) 41256

(2) 4464

(1) 4164

(2) 4464

(1) 4164

FLOPPY DRIVE SELECTION

Drives installed

SW1/7

SW1/8

1

On

On

2

Off

On

3

On

Off

4

Off

Off

MONITOR SELECTION

Type

SW1/5

SW1/6

None

On

On

Color (40 x 20)

Off

On

Color (80 x 25)

On

Off

Monochrome

Off

Off

TURBO SELECTION

Type

JP7

JP8

Always in turbo mode

Pins 1 & 2 closed

Pins 2 & 3 closed

Turbo select through software

Pins 2 & 3 closed

Pins 1 & 2 closed

Turbo select through software & keyboard

Pins 1 & 2 closed

Pins 1 & 2 closed

Note: To toggle between normal and turbo modes, press CTRL, ALT, + to enable turbo and CTRL, ALT, - to disable turbo.