************ Modification of the A2060. *******************

Legal
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This text is freeware.


What is this ?
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This Text describes how to modify the A2060 arcnetcard to make it
work in an A4000.



Why ?
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Some Arcnet 2060 don`t work properly in an A4000 or in some highly accelerated A2000`s.
(This bad behaviour doesn`t affect the A560 !!)



What is to be fixed ?
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If the board is accessed continously, e.g. when copying the card`s buffer 
into Amiga memory, a lack in the design shows up:

In the area of the LED.connector the level of 5V drops down to less than 3V.
(This effect gets even worse, if there`s a LED connected. )

The dropping voltage keeps the buffers from supplying the correct byte, the
last accessed byte is repeated instead.

(You can see this repeats using "sanamon".)

To conclude: You get lots of timeouts, unknown packets...arcnet suxx..


Let`s fix it !
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Remove the small capaticitor close to the LED.connector. (5V 2.2uF)
Solder an extra wire from the 5V and the GND to the IC (74Ls244) close to the 
LED.connector.

This should fix the prob.

I did this hack to 4 A2060`s and they all worked fine, after this hack.


Who wrote this text ?
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Email: judas@tomtec.abg.sub.org