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Text File  |  1997-12-18  |  1.8 KB  |  48 lines
  1.    ------------------ A1200 PCMCIA Slot Mod --------------------
  2.  
  3. The A1200 seems to have a bug in its Gayle chip, as the CC_RESET line
  4. does not work! The ROM code called by CardResetCard is identical to the 
  5. A600 (which does work properly) but when executed on the A1200 nothing 
  6. happens at the pin...
  7.  
  8. To fix this I developed a simple circuit that resets the card very time
  9. the bus RESET signal occurs, ie. at poweron or any system reset.
  10.  
  11. Parts required:
  12.  
  13. 1 x 22K resistor
  14. 1 x 10K resistor
  15. 1 x BC327 (or equivalent) PNP transistor
  16.  
  17.  
  18.  ------------- Diagram of the A1200 PCMCIA Card Reset mod --------------
  19.  
  20.                          ________________________
  21.                      40 /                        \
  22.       _________________|__________                X
  23.      |                            |               X 22K resistor
  24.      |               _RST         |               X
  25.      |                            |               X
  26.      |                            |  10K resistor |
  27.      |                            |   .--XXXXX----+ b
  28.      |                            |   |         __|__
  29.      |          AA Gayle          |   |           /\    PNP transistor
  30.      |                            |___|__________/  \   (eg. BC327)
  31.      |                        +5V |20           e   c|
  32.      |                            |                  |
  33.      |                            |                  |
  34.      |                            |                  |
  35.      |                CC_RESET    |                  |
  36.      |_____________o______________|                  |
  37.                    |      |                          |
  38.                   1      5 \________________________/
  39.  
  40.  Gayle pin locations
  41.  
  42.  - Pin 5 (CC_RESET) is the 5th pin from the 'pin 1' marking.
  43.  
  44.  - Pin 20 (+5V) is the 9th pin counting up the right side.
  45.  
  46.  - Pin 40 (_RST) is the 8th pin from the right, on the top.
  47.  
  48.