DuoDisk Cable Details

The diagram depicts the male end of the cable.

DB 19:

,-------------------------------------------------.
\ 01   02   03   04   05   06   07   0B   09   10 /
 \  11   12   13   14   15   16   17   18   19   /
  `---------------------------------------------'


DB 25 looking at the end of the cable:  (x = no pin)

1, 13, 22 & 25 have no pin on some OEM cables, you may need to break out a pin or pull
the blocking plug out of the connector on the disk drive. This is to keep Apple parallel & serial
cables from being plugged into the drive. But you won't do that, will you? ;-)

,----------------------------------------------------.
\ 01  02  03  04  05  06  07  08  09  10  11  12  13 /
 \  14  15  16  17  18  19  20  21  22  23  24  25  /
  `------------------------------------------------'


26 pin Header on proto Board, pin numbers line up with DB25 pins in list
+----------------------------------------------------------------+
| 14   15   16   17   18   19   20   21   22   23   24   24   26 |
| 1    2    3    4    5    6    7    8    9    10   11   12   13 |
+----------------------------------------------------------------+


Cable pin details

IIc     DB 19   DB 25      Atmega32

GND      1       2          GND to board         
GND      2       4          GND to board
GND      3       9  & 21 
GND      4       10 & 14 
-12V     5       23 
+5V      6       7          +5v to board
+12V     7       19 
+12V     8       20 
EXTINT   9       8 
WRPROT   10      12         35  PA5   (ACK for smartport)
PH0      11      15         16  PD2   (REQ for smartport)
PH1      12      16         17  PD3
PH2      13      17         18  PD4
PH3      14      18         19  PD5 
WREQ     15      5 
(NC)     16      24 
DRVEN    17      11 
RDDATA   18      3          20  PD6
WRDATA   19      6          21  PD7