IBM 770 manual Hard Disk Drive Connector, System Board

Hard Disk Drive Connector

The hard disk drive connected to the system board is removable. Figure 2-6 shows the pin assignments for the connector on the system board.

Pin	Signal	I/O	or Feature	Pin	Signal			I/O or Feature
1	DetectIn		O		31		GND	Ground
2	Jumper	A	NC		32		NC	NC
3	Jumper	B	O		33		-PDREQ	I
4	Jumper	C	O		34		GND	Ground
5	Jumper	D	O		35		-PDIOW	O
6	RSTDRV	O		36	GND			Ground
7	GND	Ground		37 -PDIOR				O
8	PDD7	I/O			38	GND		Ground
9	PDD8	I/O			39	PIORDY		I
10	GND	Ground		40		CSEL		O
11	PDD6		I/O		41		-PDACK	O
12	PDD9		I/O		42		GND	Ground
13	GND		Ground	43		IRQ14HDD		I
14	PDD5		I/O		44		-IOCS16	I
15	PDD10		I/O		45		PDA1	O
16	GND		Ground	46		-PDIAGHDD		O
17	PDD4		I/O		47		GND	Ground
18	PDD11		I/O		48		PDA0	O
19	GND		Ground	49		PDA2		O
20	PDD3		I/O		50	-CS1P		O
21	PDD12		I/O		51		-CS3P	O
22	GND		Ground	52		-DASPHDD		I
23	PDD2		I/O		53		GND	Ground
24	PDD13		I/O		54		VCC5B	Vcc
25	GND	Ground		55	VCC5B			Vcc
26	PDD1		I/O		56	VCC5B		Vcc
27	PDD14		I/O		57		VCC5B	Vcc
28	GND	Ground		58	Reserved			NC
29	PDD0	I/O			59	-HDDDETECT		I
30	PDD15		I/O		60	GND		Ground

Figure 2-6. Hard Disk Drive Connector Pin Assignments

2-8 System Board