Re: Did Commodore cheat with the quad density floppies?

From: silverdr_at_wfmh.org.pl
Date: Wed, 9 Jan 2019 11:20:06 +0100
Message-Id: <EA48861A-9538-4DA4-BB0F-3DC72590E080@wfmh.org.pl>
> On 2019-01-08, at 22:05, Gerrit Heitsch <gerrit@laosinh.s.bawue.de> 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.

AFAIR the common approach to the start-stop issue was a motor-off delay allowing consecutive accesses not to wait for the motor to spin up again.

-- 
SD! - http://e4aws.silverdr.com/
Received on 2019-01-09 12:00:29

Archive generated by hypermail 2.2.0.