WDI to IDE adaptor (6)

[Mike Arnold]

Aron, when you start looking at the PCB layout could I ask for one small change? Could you add a 22k pullup resistor from J4 pin 3 (DD7 on the IDE bus) to +5V. Let me explain.

I have redeveloped the software to handle two drives on the IDE bus (master & slave) and that all works. However, I really need to be able to detect whether a slave device is installed or not. If there is no slave unit and I try to address it then the bus will float in an indeterminate state. DD7 is the busy bit for a status read so if I find it high then I know that the slave is not installed or faulty.

If it is not possible then I can always solder a resistor on the prototype board.

Thanks

Mike

[Aron Hoekstra]

shouldn't be a problem, 1/4w or can I just go with a tiny 0603 (1/10W) surface mount part?

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[Peter Higgins]

A 1/10W SMT resistor will be fine.

[Mike Arnold]

I agree with Peter. In fact the dissipation is only 1mW so no problem. 

I am having a few snags with working out what is on the IDE bus as it appears that the master steps in if you address the slave and the master knows it's not there. Anyway, that pullup resistor will allow me to detect if no drives are connected to the bus so worth having.

Hope you had a good holiday.