ZX-25/HS, ZX-20/HS, ZX-16/HS Motherboard Settings and Configuration

Processor	80386SX
Processor Speed	16/20/25MHz
Chip Set	ACT
Max. Onboard DRAM	8MB
Cache	None
BIOS	AMI
Dimensions	218mm x 218mm
I/O Options	None
NPU Options	80387SX

CONNECTIONS
Purpose	Location	Purpose	Location
Turbo LED	JP2	External battery	JP11
Power LED & Keylock	JP5	Speaker	JP14
Reset switch	JP10	Turbo switch	JP17

USER CONFIGURABLE SETTINGS
Function		Jumper	Position
»	Factory configured - do not alter	JP3	N/A
»	Monitor type select color	JP6	pins 2 & 3 closed
	Monitor type select monochrome	JP6	pins 1 & 2 closed
»	Factory configured - do not alter	JP7	N/A
»	Factory configured - do not alter	JP8	N/A
»	Factory configured - do not alter	JP9	N/A
»	Battery select internal	JP12	pins 2 & 3 closed
	Battery select external	JP12	pins 1 & 2 closed
»	Power good signal detect from power supply	JP13	pins 1 & 2 closed
	Power good signal detect from board	JP13	pins 2 & 3 closed
»	CPU speed select 20MHz or 25MHz	JP15	pins 1 & 2 closed
	CPU speed select 16MHz	JP15	pins 2 & 3 closed
»	I/O bus speed select 8MHz	JP16	pins 1 & 2 closed
	I/O bus speed select 6MHz	JP16	pins 2 & 3 closed

DRAM CONFIGURATION
Size	Bank 0	Bank 1	Bank 2	Bank 3
512KB	(2) 256K x 9	NONE	NONE	NONE
1MB	(2) 256K x 9	(2) 256K x 9	NONE	NONE
1.5MB	(2) 256K x 9	(2) 256K x 9	(2) 256K x 9	NONE
2MB	(2) 256K x 9	(2) 256K x 9	(2) 256K x 9	(2) 256K x 9
2MB	(2) 1M x 9	NONE	NONE	NONE
3MB	(2) 256K x 9	(2) 256K x 9	(2) 1M x 9	NONE
4MB	(2) 1M x 9	(2) 1M x 9	NONE	NONE
5MB	(2) 256K x 9	(2) 256K x 9	(2) 1M x 9	(2) 1M x 9
6MB	(2) 1M x 9	(2) 1M x 9	(2) 1M x 9	NONE
8MB	(2) 1M x 9	(2) 1M x 9	(2) 1M x 9	(2) 1M x 9