44 = reserved 43 = ground
42 = Vcc +5v 41 = vcc +5v
40 = ground 39 = _DASP
38 = _CS3FX 37 = _CS1FX
36 = address line 2 35 = address line 0
34 = _PDIAG 33 = address line 1
32 = _IOCS16 31 = INTQ
30 = ground 29 = _DMACK
28 = reserved 27 = IORDY
26 = ground 25 = _DIOR
24 = ground 23 = _DIOW
22 = ground 21 = DMARQ
20 = connector key way 19 = ground
18 = data line 15 17 = data line 0
16 = data line 14 15 = data line 1
14 = data line 13 13 = data line 2
12 = data line 12 11 = data line 3
10 = data line 11 9 = data line 4
8 = data line 10 7 = data line 5
6 = data line 9 5 = data l (ine 6
4 = data line 8 3 = data line 7
2 = Ground 1 = Reset
The A1200 employs a 44 way IDE connector as used for 2.5" drives 4 pins (41-44) are used for power (5v).
Note 3.5" drives use a 40 way connector and use the same first 40 pins as in diagram, but gets its power (12v and 5v) from a separate connector.