PERSONAL SYSTEM/2 HMM Motherboard Settings and Configuration

Processor	80486SX/80486DX/80486DX2/80486DX4/P24T
Processor Speed	25/33/50(internal/66(internal)/75(internal)/100(internal)/MHz
Chip Set	Unidentified
Video Chip Set	None
Maximum Onboard Memory	Unidentified
Maximum Video Memory	None
Cache	128/256KB
BIOS	Unidentified
Dimensions	254mm x 218mm
I/O Options	32-bit PCI slots (3), floppy drive interface, IDE interfaces (2), parallel port, PS/2 mouse port, serial ports (2)
NPU Options	None

CONNECTIONS
Purpose	Location	Purpose	Location
PS/2 mouse port	J2	IDE interface 1	J21
Speaker	J5	IDE interface 2	J22
Parallel port	J8	32-bit PCI slots	PC1 – PC3
Floppy drive interface	J9	Power LED	W12
Serial port 2	J10	IDE interface LED (PCI)	W39
Serial port 1	J11	IDE interface LED (ISA)	W46

USER CONFIGURABLE SETTINGS
Function		Label	Position
»	Secondary cache write select write back	W1	Pins 2 & 3 closed
	Secondary cache write select write through	W1	Pins 1 & 2 closed
»	Internal cache write select write through	W4	Open
	Internal cache write select write back	W4	Closed
»	Flash BIOS normal operation	W6	Pins 2 & 3 closed
	Flash BIOS recovery mode	W6	Pins 1 & 2 closed
»	Factory configured - do not alter	W8	Closed
»	PS/2 mouse installed	W10	Closed
	PS/2 mouse not installed	W10	Open
	Parity generation select DPU	W17	Pins 1 & 2 closed
	Parity generation select CPU	W17	Pins 2 & 3 closed
»	DPU does not force parity	W18	Pins 2 & 3 closed
	DPU forces parity	W18	Pins 1 & 2 closed
»	Factory configured - do not alter	W19	Closed
»	Cache installed	W21	Open
	Cache not installed	W21	Closed

DRAM CONFIGURATION

Note: The maximum size and configuration is unidentified.

CACHE CONFIGURATION

Note: The location and configuration is unidentified.

CACHE JUMPER SELECTION
Size	W5	W22	W23
128KB	Open	Closed	Open
256KB	Closed	Open	Closed

CACHE TAG SELECTION
Size		W24	W26
	7-bit	Open	Closed
	8-bit	Closed	Closed
»	9-bit	Closed	Open

CPU SPEED SELECTION
Speed	W16	W20
25MHz	Open	Closed
33MHz	Closed	Open
50iMHz	Open	Closed
66iMHz	Closed	Open
75iMHz	Open	Closed
100iMHz	Closed	Open

CPU TYPE SELECTION
Type	W2	W3
80486SX	Pins 2 & 3 closed	Closed
80486DX	Pins 1 & 2, 3 & 4 closed	Closed
80486DX2	Pins 1 & 2, 3 & 4 closed	Closed
80486DX4	Pins 1 & 2, 3 & 4 closed	Closed
P24T	Pins 1 & 2, 3 & 4 closed	Open

CPU MULTIPLIER SELECTION
Multiplier	W33
1x	Pins 1 & 2 closed
2x	Pins 2 & 3 closed
3x	Open

DMA CHANNEL SELECTION
Channel		W43
»	ISA IDE used P10 transfer	Open
	6	Pins 1 & 2 closed
	7	Pins 2 & 3 closed

ISA IDE IRQ SELECTION
IRQ	W42
IRQ14	Pins 1 & 2 closed
IRQ15	Pins 2 & 3 closed

PCI IDE IRQ SELECTION
IRQ		W35	W38
»	IRQ14	Closed	Open
	IRQ15	Open	Closed

PCI INTERRUPT SELECTION
Setting	W37
INTR_A enabled	Closed
INTR_A disabled	Open

PCI COMPLIANT IRQ SELECTION
IRQ	J101
IRQ1	Pin 2
IRQ3	Pin 3
IRQ4	Pin 4
IRQ5	Pin 5
IRQ6	Pin 6
IRQ7	Pin 7
IRQ8	Pin 8
IRQ9	Pin 9
IRQ10	Pin 10
IRQ11	Pin 11
IRQ12	Pin 12
IRQ14	Pin 13
IRQ15	Pin 14