EXTERNAL DISK ...DB23 FEMALE
----------------------------

For A1000, A500, A2000 and A3000 with A2000 and A3000 differences noted.

1   RDY*                             13  SIDEB* 
2   DKRD*                            14  WPRO* 
3   GND                              15  TK0* 
4   GND                              16  DKWEB* 
5   GND                              17  DKWDB* 
6   GND                              18  STEPB* 
7   GND                              19  DIRB 
8   MTRXD*                           20  SEL3B* (A2000/A3000 not used (1))
9   SEL2B* (A2000/A3000 SEL3B* (1))  21  SEL1B* (A2000/A3000 SEL2B* (1))
10  DRESB*                           22  INDEX* 
11  CHNG*                            23  +12 
12  +5 

(1)  SEL1B*  is not drive 1, but rather the first external drive.  Not
    all select lines may be implemented.