Re: Did Commodore cheat with the quad density floppies?

On 1/8/19 9:48 PM, smf wrote:
> On 06/01/2019 13:16, Gerrit Heitsch wrote:
> 
>>
>> A drive that turns on the motor without the drive select line being 
>> active too has a design flaw. Properly designed drives would let you 
>> control the motor only if the DS line is active too.
> 
> That would require you to interrupt communication with one drive while 
> starting or stopping the motor on another.
> 
> As starting a motor takes an appreciable amount of time, it makes sense 
> to overlap them.
> 
> If starting the motor while the drive isn't selected causes problems, 
> then that is a design error.

It doesn't cause problems, it just means that you need 2 control lines 
per drive, one to select the drive and one to control its motor.

That's only possible if you limit the number of drives on a 34pin cable 
to 2 while the shugart spec allows 4.

  Gerrit