INTEL CORPORATION
R486SX254F/R486SX33F/R486DX334F/R486DX2664F
| 
 Processor  | 
 80486SX/80487SX/80486DX/ODP486SX/80486DX2/Pentium Overdrive  | 
| 
 Processor Speed  | 
 25/33/50(internal)/66(internal)MHz  | 
| 
 Chip Set  | 
 VLSI  | 
| 
 Max. Onboard DRAM  | 
 32MB  | 
| 
 Cache  | 
 64/128/256KB  | 
| 
 BIOS  | 
 Phoenix  | 
| 
 Dimensions  | 
 330mm x 218mm  | 
| 
 I/O Options  | 
 32-bit proprietary riser card slot, floppy drive interface,IDE interface, parallel port, PS/2 mouse port,serial ports (2), VGA feature connector, VGA port  | 
| 
 NPU Options  | 
 None  | 

| 
 CONNECTIONS  | 
|||
| 
 Purpose  | 
 Location  | 
 Purpose  | 
 Location  | 
| 
 VGA port  | 
 J1  | 
 Floppy drive interface  | 
 J15  | 
| 
 Parallel port  | 
 J2  | 
 +5V auxiliary fan power  | 
 J26  | 
| 
 Serial port 2  | 
 J3  | 
 IDE interface LED  | 
 J29  | 
| 
 Serial port 1  | 
 J4  | 
 Power LED & Keylock  | 
 J30  | 
| 
 PS/2 mouse port  | 
 J5  | 
 Reset switch  | 
 J31  | 
| 
 32 Bit proprietary riser card  | 
 J7  | 
 +12V auxiliary fan power  | 
 J32  | 
| 
 VGA feature connector  | 
 J10  | 
 External speaker  | 
 J33  | 
| 
 IDE interface  | 
 J14  | 
 
  | 
 
  | 
| 
 Note:To connect an external speaker, remove the jumper from pins 3 & 4 and connect external speaker between pins 1 & 4.  | 
|||
| 
 USER CONFIGURABLE SETTINGS  | 
|||
| 
 Function  | 
 Jumper  | 
 Position  | 
|
| 
 »  | 
 FLASH BIOS programming enabled  | 
 J12  | 
 pins 1 & 2 closed  | 
| 
 
  | 
 FLASH BIOS programming disabled  | 
 J12  | 
 pins 2 & 3 closed  | 
| 
 »  | 
 Normal FLASH operation  | 
 J13  | 
 pins 1 & 2 closed  | 
| 
 
  | 
 Invoke boot block recovery  | 
 J13  | 
 pins 2 & 3 closed  | 
| 
 »  | 
 Enable onboard video  | 
 J16  | 
 pins 1 & 2 closed  | 
| 
 
  | 
 Disable onboard video  | 
 J16  | 
 pins 2 & 3 closed  | 
| 
 »  | 
 Disable floppy drive write protect  | 
 J17  | 
 pins 2 & 3 closed  | 
| 
 
  | 
 Enable floppy drive write protect  | 
 J17  | 
 pins 1 & 2 closed  | 
| 
 »  | 
 Enable password  | 
 J20  | 
 pins 2 & 3 closed  | 
| 
 
  | 
 Disable password  | 
 J20  | 
 pins 1 & 2 closed  | 
| 
 »  | 
 Enable user to enter Setup  | 
 J21  | 
 pins 1 & 2 closed  | 
| 
 
  | 
 Prevent user to enter Setup  | 
 J21  | 
 pins 2 & 3 closed  | 
| 
 »  | 
 CMOS normal operation  | 
 J28  | 
 Closed  | 
| 
 
  | 
 CMOS clear upon power-up  | 
 J28  | 
 Open  | 
| 
 DRAM CONFIGURATION  | 
||
| 
 Size  | 
 Bank 0  | 
 Bank 1  | 
| 
 2MB  | 
 (1) 512K x 36  | 
 NONE  | 
| 
 4MB  | 
 (1) 512K x 36  | 
 (1) 512K x 36  | 
| 
 4MB  | 
 (1) 1M x 36  | 
 NONE  | 
| 
 6MB  | 
 (1) 512K x 36  | 
 (1) 1M x 36  | 
| 
 6MB  | 
 (1) 1M x 36  | 
 (1) 512K x 36  | 
| 
 8MB  | 
 (1) 1M x 36  | 
 (1) 1M x 36  | 
| 
 8MB  | 
 (1) 2M x 36  | 
 NONE  | 
| 
 10MB  | 
 (1) 2M x 36  | 
 (1) 512K x 36  | 
| 
 10MB  | 
 (1) 512K x 36  | 
 (1) 2M x 36  | 
| 
 12MB  | 
 (1) 2M x 36  | 
 (1) 1M x 36  | 
| 
 16MB  | 
 (1) 1M x 36  | 
 (1) 2M x 36  | 
| 
 16MB  | 
 (1) 2M x 36  | 
 (1) 2M x 36  | 
| 
 16MB  | 
 (1) 4M x 36  | 
 NONE  | 
| 
 18MB  | 
 (1) 512K x 36  | 
 (1) 4M x 36  | 
| 
 18MB  | 
 (1) 4M x 36  | 
 (1) 512K x 36  | 
| 
 20MB  | 
 (1) 1M x 36  | 
 (1) 4M x 36  | 
| 
 20MB  | 
 (1) 4M x 36  | 
 (1) 1M x 36  | 
| 
 24MB  | 
 (1) 2M x 36  | 
 (1) 4M x 36  | 
| 
 24MB  | 
 (1) 4M x 36  | 
 (1) 2M x 36  | 
| 
 32MB  | 
 (1) 4M x 36  | 
 (1) 4M x 36  | 
| 
 CACHE CONFIGURATION  | 
|||
| 
 Size  | 
 Bank 0  | 
 Bank 1  | 
 TAG  | 
| 
 64KB  | 
 (4) 8K x 8  | 
 (4) 8K x 8  | 
 (1) 32K x 8  | 
| 
 128KB  | 
 (4) 32K x 8  | 
 NONE  | 
 (1) 32K x 8  | 
| 
 256KB  | 
 (4) 32K x 8  | 
 (4) 32K x 8  | 
 (1) 32K x 8  | 
| 
 CACHE JUMPER CONFIGURATION  | 
|
| 
 Size  | 
 J11  | 
| 
 64KB  | 
 Open  | 
| 
 128KB  | 
 pins 1 & 2, 5 & 6 closed  | 
| 
 256KB  | 
 pins 1 & 2, 3 & 4, 7 & 8 closed  | 
| 
 CPU TYPE CONFIGURATION  | 
||||
| 
 CPU Type  | 
 J22  | 
 J23  | 
 J24  | 
 J25  | 
| 
 80486SX  | 
 pins 1 & 2 closed  | 
 pins 2 & 3 closed  | 
 pins 2 & 3 closed  | 
 pins 2 & 3 closed  | 
| 
 80487SX  | 
 pins 2 & 3 closed  | 
 pins 1 & 2 closed  | 
 pins 2 & 3 closed  | 
 pins 1 & 2 closed  | 
| 
 80486DX  | 
 pins 2 & 3 closed  | 
 pins 1 & 2 closed  | 
 pins 1 & 2 closed  | 
 pins 2 & 3 closed  | 
| 
 80486DX2  | 
 pins 2 & 3 closed  | 
 pins 1 & 2 closed  | 
 pins 1 & 2 closed  | 
 pins 2 & 3 closed  | 
| 
 ODP486SX  | 
 pins 2 & 3 closed  | 
 pins 1 & 2 closed  | 
 pins 2 & 3 closed  | 
 pins 1 & 2 closed  | 
| 
 CPU SPEED CONFIGURATION  | 
||
| 
 CPU Speed  | 
 J18  | 
 J19  | 
| 
 25MHz  | 
 pins 1 & 2 closed  | 
 pins 1 & 2 closed  | 
| 
 33MHz  | 
 pins 1 & 2 closed  | 
 pins 2 & 3 closed  | 
| 
 50iMHz  | 
 pins 1 & 2 closed  | 
 pins 1 & 2 closed  | 
| 
 66iMHz  | 
 pins 1 & 2 closed  | 
 pins 2 & 3 closed  | 
| 
 VRAM CONFIGURATION  | 
||
| 
 Size  | 
 Bank 0  | 
 Bank 1  | 
| 
 512K  | 
 (4) 256 x 4  | 
 NONE  | 
| 
 1MB  | 
 (4) 256 x 4  | 
 (4) 256 x 4  |