Processor	80486DX
Processor Speed	25MHz
Chip Set	Tandy
Max. Onboard DRAM	64MB
SRAM Cache	256KB
BIOS	Phoenix
Dimensions	355mm x 304mm
I/O Options	EGA feature connector, floppy drive interface, IDE interface, parallel port, serial port (2), VGA port (on external I/O card)
NPU Options	4167

CONNECTIONS
Purpose	Location	Purpose	Location
External battery	J3	Reset switch	W5
Speaker	J15	Turbo switch	W6
Power LED & keylock	J16	Turbo LED	W7

USER CONFIGURABLE SETTINGS
Function		Jumper	Position
»	CMOS memory normal operation	J2	open
	CMOS memory clear	J2	closed
»	Factory configured - do not alter	W1	N/A

SRAM CONFIGURATION
Size	Bank 0	W3	W4
256KB	(8) 32K x 8	closed	closed

DRAM CONFIGURATION
Size	Bank 0	Bank 1	Bank 2	Bank 3
4MB	(4) 1M x 9	NONE	NONE	NONE
8MB	(4) 1M x 9	(4) 1M x 9	NONE	NONE
12MB	(4) 1M x 9	(4) 1M x 9	(4) 1M x 9	NONE
16MB	(4) 1M x 9	(4) 1M x 9	(4) 1M x 9	(4) 1M x 9
16MB	(4) 4M x 9	NONE	NONE	NONE
20MB	(4) 1M x 9	(4) 4M x 9	NONE	NONE
24MB	(4) 1M x 9	(4) 1M x 9	(4) 4M x 9	NONE
28MB	(4) 1M x 9	(4) 1M x 9	(4) 1M x 9	(4) 4M x 9
32MB	(4) 4M x 9	(4) 4M x 9	NONE	NONE
36MB	(4) 1M x 9	(4) 4M x 9	(4) 4M x 9	NONE
40MB	(4) 1M x 9	(4) 1M x 9	(4) 4M x 9	(4) 4M x 9
48MB	(4) 4M x 9	(4) 4M x 9	(4) 4M x 9	NONE
52MB	(4) 1M x 9	(4) 4M x 9	(4) 4M x 9	(4) 4M x 9
64MB	(4) 4M x 9	(4) 4M x 9	(4) 4M x 9	(4) 4M x 9

DRAM SWITCH CONFIGURATION
Size	SW2/switch 1	SW2/switch 2	SW2/switch 3	SW2/switch 4	SW2/switch 5
4MB	closed	closed	closed	closed	closed
8MB	open	closed	closed	closed	closed
12MB	closed	open	closed	closed	closed
16MB	open	open	closed	closed	open
16MB	closed	closed	open	closed	open
20MB	closed	closed	open	open	open
24MB	closed	open	closed	open	open
28MB	open	closed	closed	open	open
32MB	open	closed	open	closed	open
36MB	closed	open	open	open	open
40MB	open	open	closed	open	open
48MB	closed	open	open	closed	open
52MB	open	open	open	open	open
64MB	open	open	open	closed	open

CONNECTIONS
Purpose	Location	Purpose	Location
IDE drive interface	J1	Serial port 2	J5
Floppy drive interface	J2	IDE interface LED	J6
Parallel port	J3	VGA feature	J7
Serial port 1	J4	EGA feature	J11

SERIAL PORT 1 (J4) CONFIGURATION S1
Function	Switch 1	Switch 2	Switch 3	Switch 4	Switch 5	Switch 6
disabled	open	open	open	open	open	open
COM1/IRQ4	closed	open	open	open	open	closed
COM2/IRQ3	open	closed	open	open	closed	open
COM3/IRQ4	open	open	closed	open	open	closed
COM4/IRQ3	open	open	open	closed	closed	open

SERIAL PORT 2 (J5) CONFIGURATION S3
Function	Switch 1	Switch 2	Switch 3	Switch 4	Switch 5	Switch 6
disabled	open	open	open	open	open	open
COM1/IRQ4	closed	open	open	open	open	closed
COM2/IRQ3	open	closed	open	open	closed	open
COM3/IRQ4	open	open	closed	open	open	closed
COM4/IRQ3	open	open	open	closed	closed	open

PARALLEL PORT (J3) CONFIGURATION S2
Function	Switch 1	Switch 2	Switch 3	Switch 4	Switch 5	Switch 6
disabled	open	open	open	N/A	open	open
LPT1/IRQ7	closed	open	open	N/A	open	closed
LPT2/IRQ5	open	closed	open	N/A	closed	open
LPT3/IRQ7	open	open	closed	N/A	open	closed

USER CONFIGURABLE SETTINGS
Function		Jumper	Position
»	IOCHRDY signal from pin 27 enabled	J8 J9	open open
»	IOCHRDY signal from pin 21 enabled	J8 J9	closed closed
»	IDE interface pin 34 select PDIAG signal	J10	open
	IDE interface pin 34 select ground	J10	closed
»	Floppy drive interface precompensation mode select 125ns	J12	open
	Floppy drive interface precompensation mode select 187ns	J12	closed
»	IDE interface (J1) enabled	J14	closed
	IDE interface (J1) disabled	J14	open
»	On-board video enabled	J15	closed
	On-board video disabled	J15	open
»	Floppy drive interface (J2) interrupt request select IRQ6	J16	closed
	Floppy drive interface (J2) interrupt request select none	J16	open
»	Single speed motor select	J17	open
	Dual speed motor select	J17	closed
»	On-board video select 16-bit mode normal	J18	open
	On-board video force 8-bit mode	J18	closed
»	Floppy drive disk change signal enabled	J19	closed
	Floppy drive disk change signal disabled	J19	open
»	Monitor type select color	J20	pins 1 & 2 closed
	Monitor type select monochrome	J20	pins 2 & 3 closed
	VGA feature connector disabled	J22	closed
	VGA feature connector enabled	J22	open
»	Floppy drive interface (J2) enabled	J23	closed
	Floppy drive interface (J2) disabled	J23	open
»	IDE interface (J1) interrupt request select IRQ14	J24	closed
	IDE interface (J1) interrupt request select none	J24	open