40 Pin to 50 Pin SCSI Adapter wiring

Here is a simple wiring diagram to use the BlueSCSI desktop version to backup 2.5” 40 pin SCSI drives.

The wiring description is intended for modifying a simple 2.5” IDE cable that will be split up in several chunks and then inserted into a 2x25 pin 2.54mm IDC connector.

  SCSI      SCSI
  40pin     50pin

   1   +5V      ext. Supply
   2   +5V      ext. Supply
                             i.e. Molex
   3   GND      ext. Supply
   4   GND      ext. Supply

   5   GND   1
   6   DB0   2  
   7   GND   3
   8   DB1   4
   9   GND   5
  10   DB2   6
  11   GND   7
  12   DB3   8
  13   GND   9
  14   DB4  10
  15   GND  11
  16   DB5  12
  17   GND  13
  18   DB6  14
  19   GND  15
  20   DB7  16
  21   GND  17
  22   DBP  18
            19
            20
            21
            22
            23
            24
  23   GND  25 
  24   TERM 26  (or +5V supply on 40p side)
            27
            28
            29
            30
            31
  25   ATN  32
            33
            34
            35
  26   BSY  36
  27   GND  37
  28   ACK  38
            39
  29   RST  40
            41
  30   MSG  42
  31   GND  43
  32   SEL  44
            45
  34   C/D  46
  35   GND  47
  36   REQ  48
            49
  33   I/O  50  (yes, this pin is "out of order")

  37   GND      ext. Supply
  38   GND      ext. Supply
                             i.e. Molex
  39   +5V      ext. Supply
  40   +5V      ext. Supply

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