50pin interface for notebook to 40pin interface for standard ATA:
Original article: http://pinouts.ru/DiskCables/cdrom_40to50_pinout.shtml
ATA (40) PIN CD-ROM (50) PIN Name Description
1 audio left
2 audio right
3 audio ground
2 4 Gnd ground
1 5/Reset
4 6 dd8 data 8
3 7 dd7 data 7
6 8 dd9 data 9
5 9 DD6 data 6
8 10 dd10 data 10
7 11 dd5 data 5
10 12 dd11 Data 11
9 13 DD4 data 4
12 14 dd12 data 12
11 15 DD3 data 3
14 16 dd13 data 13
13 17 dd2 data 2
16 18 dd14 data 14
15 19 DD1 data 1
18 20 dd15 data 15
17 21 dd0 DATA 0
21 22 dmarq DMA request
19 23 Gnd ground
25 24/Dior read strobe
23 25/diow write strobe
22 26 Gnd ground
27 27 iordy I/O ready
29 28/dmack DMA acknowledge
31 29 intrq interrupt request
32 30/iocs16 Io chipselect 16
33 31 da1 address 1
34 32 pdiag passed diagnostics
35 33 da0 address 0
36 34 da2 address 2
37 35/ide_cs0 (1f0-1f7)
38 36/ide_cs1 (3f6-3f7)
39 37/active-/dasi-dasp LED driver
+ 5 V 38 + 5 V + 5 volts power
+ 5 V 39 + 5 V + 5 volts power
+ 5 V 40 + 5 V + 5 volts power
+ 5 V 41 + 5 V + 5 volts power
+ 5 V 42 + 5 V + 5 volts power
24 43 Gnd ground
26 44 Gnd ground
30 45 Gnd ground
40 46 Gnd ground
28 47 device CFG spindle sync or cable select
Ground 48 Gnd ground
49 reserved vendor unique
50 reserved vendor unique
Article Source: http://www.hesicong.net/pjblog/default.asp? Id = 193