8" drive support on PC's

[Randy McLaughlin]

On the Nec 765 (Intel 8272) the direction pin is also use for reduced write 
current (TG43).

When the step line pulses the direction pin controls the direction.  All 
other times it is high if the track counter is 43 or less, low if the track 
counter is greater than 43.

The current disk controllers are based on the 765.

Does anyone know if the direction pin does the same on the newer clone 
chips?  I have started looking at the datasheets but so far I have not found 
any reference to that function on "modern" parts.

If it's true then the 34 to 50 pin cable I use (and others) can be made to 
include TG43 without using an adapter like FDADAP.

It may turn out some do and some don't but since everyone is basically using 
the same licensed core I would expect all newer chips to act the same.  The 
question is was TG43 support kept from the original 765?


Randy
www.s100-manuals.com