Conference hydra::amiga_v1

    I just saw an ad in the August AmigaWorld for the new AMAX II and
    AMAX II Plus emulation software/hardware for the Amiga.  It allows
    use of hard disk partitions and some other bells and whistles. 
    AMAX II Plus is a card for the A2000 which gives MAC serial ports
    and allows full use of midi ports.  It also says it can use the
    Amiga native 3.5 in drives to read/write MAC disks.  
    

>	It also says it can use the
>	Amiga native 3.5 in drives to read/write MAC disks.  
    
I wonder how they did that? Maybe they write those partially formatted 
disks that can be read on either machine but only hold about 128K.

I thought the Mac drives were variable speed and it was not possible to 
simulate this with the Amiga drives.

Randy

    Actually, the AMAX II harware card will be able to read/write Amiga and
    MAC disks on standard amiga drives. I am having trouble believing it
    myself having recently taken a course which discussed floppies and
    floppy controllers in some detail... But, they say it will be able to.
    
    If it can, and I bet it will, I will be buying it ASAP.
    
    bob
    refine::pomeroy
    
    (not that I really want to run MAC software too often, but it will
    probably come in useful. If you get one, show it to your friends who
    want to buy MACs, maybe they will change their minds and go Amiga!)
    

    David Small of the Atari ST Mac emulator fame, has had his emulator
    reading & writing mac disks for some time now.  I read an interview
    with him where he talked about how reading mac disks could be done:
    
     the mac disk is written at different speeds depending on where
     your are on the disk.  To read it you need to be able to vary
     the speed, 3 possible ways:
     1. require a real mac floppy disk drive
     2. vary the speed by pulsing the motor on/off rapidly
     3. custom hardware so that you can read the disk at 300rpm and
        then translate the raw data in software, based on the speed
        you know the data was written at.
    
    I believe he went with #3.
    
    Dave
                                

    Re: .4
    
    Both methods 2 and 3 are possibilities with the Amax-II+ card.
    Remember the Disk2Disk software form CSC? While it wasn't too
    successful, it sometimes (or often on some drives ;-) was able to read
    1541 disks which are also accessed at different speeds, by pulsing the
    disk motor thru software.
    I'd assume that a hardware driven pulse could be stable enough to work.
    If they choose method 3, this would mean that they have to switch the
    entire drive bus which makes this solution despite the additional
    hardware the most expensive one short of #1. ;-)
    
    <CB>

    re:.5
    
    Is it just me, or does that pulsing the drive motor scheme seem like
    a good way to shorten the life of your floppy drive?
    
    Maybe the custom hardware solution might not be needed for the Amiga,
    after all, the ST does have a Western Digital floppy controller chip to
    deal with.
    
    I'd settle for a 1.44 meg floppy drive that could handle Mac, ibmpc,
    and Amiga disks, even if it meant a new floppy controller.  Although
    some of the hints on usenet implied that there was a software way
    of supporting it.
    
    The mystery shouldn't last too long, right?  After all, Readysoft is
    running ads so they can't be too far from actually shipping :-)
    I wonder if they are talking to the Appied Engineering folks about
    1.44 meg floppy drives...
    
    Dave
    

    
    I remember a few years back UK Amiga whiz Jez San (StarGlider)
    commented that one could easily perform 'software quantizing of the
    data stream' to read Mac disks.  He even threatened to do it himself if
    he ever had a spare ten mimutes. :^)
    
    Ed.