The SPARCengine 5 is a UltraSPARC-based single-board computer produced by Sun Microsystems in the mid-1990s. Its motherboard uses a proprietary 18-pin power connector that carries the standard DC voltage rails (+12 V, −12 V, +5 V) together with system control signals including power on/off, fan control, and an AC outlet sense or switched-outlet signal. This arrangement differs markedly from later ATX-family connectors: the SPARCengine Ultra AXi (1999), for example, migrated to a standard 20-pin ATX connector (Molex 39-29-9202), while the earlier SPARCclassic/SPARCstation LX used a 12-pin proprietary connector. The 18-pin configuration documented here is specific to the SPARCengine 5 board and is not electrically or mechanically interchangeable with any standard ATX supply.
| Pin | Description |
|---|---|
| 1 | +12 |
| 2 | -12 |
| 3 | +5 |
| 4 | +5 |
| 5 | +5 |
| 6 | +5 |
| 7 | +5 |
| 8 | +5 |
| 9 | Power off |
| 10 | Ground |
| 11 | Ground |
| 12 | Ground |
| 13 | Ground |
| 14 | Ground |
| 15 | Ground |
| 16 | AC Outlet |
| 17 | Fan |
| 18 | Power on |
Signals
- +12 — +12 V DC supply rail.
- -12 — −12 V DC supply rail.
- +5 — +5 V DC supply rail; multiple pins are used in parallel to distribute current load across the connector.
- Power off — active signal to command the power supply to shut down; functionally analogous to the PS_ON signal in ATX.
- Power on — asserted by the power supply or system logic to indicate the supply is active and voltages are within specification; similar in intent to the PWR_OK/PW_OK line used on later Sun workstation boards.
- Ground — DC return; multiple ground pins are distributed across the connector.
- AC Outlet — signal or switching line associated with a controlled AC outlet.
- Fan — fan control or fan tachometer signal; used to monitor or regulate chassis cooling. Later Sun workstation boards (SPARCengine Ultra AXi) moved fan management outside the main power connector.
Notes
- The connector is proprietary to the SPARCengine 5 platform and cannot be replaced by a standard ATX, AT, or later Sun ATX-style power supply without adaptation.
- This connector is proprietary; Sun Microsystems did not publish an official specification for it.
- The presence of an AC Outlet pin is unusual for a board-level DC power header.
- Connector orientation, keying, and housing part number are not publicly documented.
References
- SPARCengine Ultra AXi OEM Technical Manual (Part No. 805-3158-03, May 1999) — Appendix A, TABLE A-12: ATX Power Connector J1901 — Sun Microsystems.
- SPARCclassic/SPARCclassic X/SPARCstation LX Service Manual (Part No. 801-2176-13, Revision A, November 1993) — Chapter 4, TABLE 4-2: Power Supply Connector — Sun Microsystems.