8 pin DIN female connector at the motherboard.
The PS/2 mouse header on the Hsin Tech TX PRO-II mainboard (marketed as PC Chips M571, El Pina, M-Compa, and numerous other OEM brand names) is an 8-pin on-board header at board position PS2. The TX PRO-II is a Baby AT-form-factor Socket 7 board built around the SiS 5598 chipset, produced circa 1997–1998. Of the eight pin positions, only four carry electrical signals — Mouse CLK, Mouse Data, +5 VDC, and Ground — with pins 3, 5, 6, and 7 explicitly documented as no-connect in the manufacturer’s manual. The PS/2 serial interface uses open-collector Clock and Data lines operating at approximately 10–16.7 kHz with TTL logic levels and a +5 V supply.
| Pin | Name | Description |
|---|---|---|
| 1 | clock | mouse clock |
| 2 | Vss | ground |
| 3 | nc | no connection |
| 4 | data | mouse data |
| 5 | nc | no connection |
| 6 | nc | no connection |
| 7 | nc | no connection |
| 8 | Vcc | +5vdc |
Signals
- clock — bidirectional PS/2 clock line, open-collector, device-generated at approximately 10–16.7 kHz; host latches data on the falling edge
- Vss — signal and supply ground
- nc — no connection; pins 3, 5, 6, and 7 are unpopulated and carry no signal
- data — bidirectional PS/2 serial data line, open-collector; frames consist of one start bit, eight data bits (LSB first), one odd-parity bit, and one stop bit
- Vcc — +5 VDC supply for the PS/2 mouse device
Notes
- Both Clock and Data lines are open-collector with pull-up to +5 V; standard TTL logic levels apply.
- An alternative path to the same PS/2 mouse interface exists on some board variants via the J7 ATX Form Card Connector (18-pin): pins 5, 6, 15, and 16 carry +5 VDC, Mouse CLK, Mouse Data, and Ground respectively.
- The keyboard connector (KBD) on the same board is a 5-pin female DIN (AT-style) and is separate from this PS/2 mouse header.
- IRQ12 is assigned to the PS/2 mouse in the board BIOS.
- This is a proprietary OEM on-board header; it is not defined by any public industry standard.