Conference hydra::amiga_v1

2501.0. "drive ID's and ready signal ??" by KLO::COLLINS (STEVE) Mon Apr 24 1989 19:28

    Can some one give me a little more background on the way floppy
    dive signals are stepped down .I'm a little confused.
    
    I've seen references to all the drive select signals being chained
    together and stepped down as they come out of each addon drive.

    I don't understand this .I thought that each of the external drives
    had its own individual sel line .Also I don't fully understand the
    ready signal . I thought the way it works is that the amiga asserts
    each of the select lines in turn and waits for the drive ID to come
    back on the ready line .Does the ID come back just as a short burst
    or is it continuous when the sel line for that drive is asserted.
    Is the ready line from the drive itself connected directly to the
    ready line going to the amiga .
    
    In particular I'm thinking of adding a 5 1/4 " and 1 possibly two
    3 1/2 " floppys to my system using the circuits that I've seen floating
    around on the net for the different drive ID'S but they show both
    the ready line from the drive and the drive ID from the addon circuit
    connected to the ready line going back to the ready pin on the amiga
    floppy connector ,I don't understand how these don't conflict with
    one another.
    
    Confused
    
    Steve...
    
    

    Hi , Steve 
    
    Thanx for your mail , i will answer you in more detail during this
    week.
    well , ive been out four a couple of weeks and at the moment very
    busy with job related tasks so i like this way to give you a 
    short notice.
    
    bye for now , Ingo 
    

    Would you please put the replys in the notes file. I'm too interested
    in this subject.  I have 3 AT type drive hooked into a circuit that
    was posted on the usenet and also to the notes file.  The circuit
    works great with one big BUT or EXCEPTION.  That is, there is a
    call ( I don't know wich one it is ) that send a signal to the drive
    and expects an answer of some type.  It could have to deal with
    either the ready line or the disk change line.  Programs like NIB
    use this call and my screen goes flaky.  Another some sort of window
    backup responds (returns error) `drive not ready'.  I have a feeling
    that it is looking for the device type.  The drives are recognized
    by both cli and workbench without any modifications to the mountlist.
    
    I have learned to live with the problem.  Any help in resolving 
    the problem would be great.
    
    Thanks,
    pete