AST RESEARCH, INC.
PREMIUM 4/25S III (501290-001)
| Device Type | Mainboard |
| Processor | 80486SX/80486SX2 |
| Processor Speed | 25MHz |
| Chip Set | Unidentified |
| Video Chip Set | Cirrus Logic |
| Maximum Onboard Memory | 64MB |
| Maximum Video Memory | Unidentified |
| BIOS | Unidentified |
| Dimensions | Unidentified |
| I/O Options | 16-bit ISA slots (4), IDE interface, parallel port, PS/2 mouse port, PS/2 mouse interface, serial ports (2), VGA port, cache slot, AT power connectors (2) |
CONNECTIONS |
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| Purpose | Location |
Purpose | Location |
| AT1 power connector 1 | AT1 |
PS/2 mouse port | CN6 |
| AT1 power connector 2 | AT2 |
16-bit ISA slots | IS1 - IS4 |
| VGA port | CN1 | IDE interface 1 | J22 |
| AT keyboard port | CN2 | Floppy drive interface | J24 |
| Parallel port | CN3 | Speaker | J27 |
| Serial port | CN4 | Fan power | J28 |
| Serial port | CN5 | Front console LEDs | J29 |
USER CONFIGURABLE SETTINGS |
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Function |
Label |
Position |
|
» |
Color display mode enabled | E4 | Closed |
| Monochrome display mode enabled | E4 | Open |
|
| » | Integrated video enabled | E5 | Closed |
|
Integrated video disabled | E5 |
Open |
| » | Password enabled | E6 | Closed |
| Password disabled | E6 | Open |
|
» |
Parallel port IRQ 7 | E12 |
Pins 1 & 2 closed |
| Parallel port IRQ 5 | E12 |
Pins 2 & 3 closed |
|
SIMM CONFIGURATION |
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Size |
Bank 0 |
Bank 1 |
8MB |
(2) 1M x 36 |
None |
16MB |
(2) 2M x 36 |
None |
16MB |
(2) 1M x 36 |
(2) 1M x 36 |
24MB |
(2) 2M x 36 |
(2) 1M x 36 |
32MB |
(2) 4M x 36 |
None |
32MB |
(2) 2M x 36 |
(2) 2M x 36 |
40MB |
(2) 4M x 36 |
(2) 1M x 36 |
48MB |
(2) 4M x 36 |
(2) 2M x 36 |
64MB |
(2) 4M x 36 |
(2) 4M x 36 |
CACHE JUMPER CONFIGURATION |
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Size |
E1 | E2 | E3 | |
| » | 64KB or None | Open | Open | Open |
| 256KB | Closed | Closed | Closed | |
CPU SPEED SELECTION |
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Speed |
E9 | E10 |
25MHz |
Closed | Closed |
33MHz |
Open | Closed |
CPU TYPE SELECTION |
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Type |
E11 | E13 | E14 | E15 | E16 | E17 |
| 486SX (PQFP) | Open | Open | 1 & 2 | 1 & 2 | 1 & 2 | 1 & 2 |
| 486SX (LIF) | Closed | Open | 1 & 2 | 1 & 2 | 1 & 2 | 1 & 2 |
| 486DX | Closed | Closed | 2 & 3 | 1 & 2 | 2 & 3 | 1 & 2 |
| 486DX2 | Closed | Closed | 2 & 3 | 1 & 2 | 2 & 3 | 1 & 2 |
| ODPR | Closed | Closed | 2 & 3 | 1 & 2 | 2 & 3 | 1 & 2 |
| ODP | Closed | Closed | 1 & 2 | 1 & 2 | 2 & 3 | 1 & 2 |
| 487SX | Closed | Closed | 1 & 2 | 1 & 2 | 2 & 3 | 1 & 2 |
| Pentium OD | Closed | Closed | 2 & 3 | 2 & 3 | 2 & 3 | Open |
| Note: Pins designated should be in the closed position. | ||||||