Mitac MTC IH4077C 

Processor: 80486SX/80486DX/80486DX2/P23N/Pentium Overdrive
Processor Speed: 25/33/40/50/50(internal)/66(internal)/80(internal) MHz
Chip Set: UMC UM82C491F
Max. Onboard DRAM: 32MB 
Cache: 0/64/128/256KB 
BIOS: Award
Dimensions: 254mm x 218mm (10" x 8.5")
I/O Options: 32-bit VESA local bus slots (2) 
NPU Options: None 


CONNECTIONS:
Purpose 		Location
Internal battery 	J1 
External battery 	J2 
Reset switch 		J4
Power LED		J5
Turbo switch		J6
Keylock			J7 
Speaker 		J8 
32-bit VESA local bus	MCA1 & MCA2


USER CONFIGURABLE SETTINGS 
Function				Jumper		Position
VESA Slot 1 and Slot 2 (MCA1 + MCA2)	JP2		pins 1 & 2 closed*
VESA Only Slot1 (MCA1)			JP2		pins 2 & 3 closed 
VL-BUS 1 Wait state			JP7		pins 1 & 2 closed*
VL-BUS 0 Wait state			JP7		pins 2 & 3 closed
Factory configured - do not alter 	JP8		No jumpers*
PQFP CPU Disabled			JP17		Closed*
PQFP CPU Enabled			JP17		Open
Factory configured - do not alter	JP19		Closed*
Factory configured - do not alter	JP20		Open*
	* = Default

DRAM CONFIGURATION
Size	Bank 0 		Bank 1
4MB	(4) 1M x 9 	NONE
8MB	(4) 1M x 9 `	(4) 1M x 9
16MB	(4) 4M x 9 	NONE
32MB	(4) 4M x 9 	(4) 4M x 9 


CACHE CONFIGURATION
Size	Bank 0 		Bank 1 		TAG
64KB	
128KB	(4) 32K x 8 	NONE		(1) 8K x 8 
256KB	(4) 32K x 8 	(4) 32K x 8 	(1) 32K x 8


CACHE JUMPER CONFIGURATION (see Cache Note below)
Size	JP9	JP10	JP11	JP12
64K	1 & 2	Open	Open	Open
128K	2 & 3	2 & 3	Open	Close
256K	1 & 2	1 & 2	Close	Close


CPU TYPE CONFIGURATION
Type		JP14		JP15
80486SX		Open		pins 2 & 3 closed
80486DX		1 & 2 closed	1 & 2, 3 & 4 closed
80486DX2	1 & 2 closed	1 & 2, 3 & 4 closed
P23N / T	2 & 3 closed 	1 & 2, 3 & 4 closed


CPU SPEED CONFIGURATION 
Clock Speed	JP6	JP5	JP4
25MHz		Open	Open	Closed
33MHz		Closed	Closed	Open
40MHz		Open	Closed	Closed
50MHz		Closed	Open	Open


BUS SPEED CONFIGURATION 
CPU speed 	JP16
<= 33MHz 	Open
>  33MHz	Closed


Cache Note: If No cache memory is installed and the Cache Size jumpers are set,
the board will successfully boot reporting 0 cache.

