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External Link interface

From GeekDotWiki


The external buffered interface is not fitted by default. The buffering of the external link interface allows longer cables to an external Transputer farm (max. 2 meters).

To use it you will need to add some extra components to the bottom side of the card:

  • one 5V, TSOP48, 74xx162245 buffer (IC5)
  • 4x 0603 100nF caps (C19/21/22/23)
  • 2x6 90° Pinheader to the edge of the card
  • a 10k resistor
  • a shottky diode

Due to a f-up by the idiot who designed the card (forgot his name), you need to do some fixing:

  • Do not solder pin 32 of the 74xx162245 to the PCB but lift it a bit upwards from the PCB (BLUE ARROW)
  • (optional but recommended) cut the trace leading to pin 32 (RED mark)
  • Solder the resistor and the diode in parallel to the "ERROR" pin of the nearby TRAM socket. (YELLOW mark)
  • The cathode (that's the end normally marked with a white stripe) of the diode need to be connected towards pin 32 of the buffer

This solder stunt is not for the fainthearted - don't drink too much coffee before doing this. Shaky hands won't help here. A microscope will help dramatically and you might need a very thin wire to be soldered to that pin.

Here's a piccy of the whereabouts... [attachment=0]External-Fix.jpg[/attachment]

Sorry for this, but I was assuming that out of the 50 1st batch owners 1 or max. 2 will actually own an external Transputer farm to be attached to the ATW800/2.

A simpler solution

Another more crude but simpler solution would be to directly connect an external TRAM to the TRAM socket of the ATW800/2. The cable would be limited to roughly 30-50cm but all you'd need would be 5 cables (given there's external 5V provided):

  • Link0 in
  • Link0 out
  • Analyze
  • Reset
  • Error