External floppy drive for Amiga 500 Options
Alex
I'm trying to find an external floppy drive for my Amiga 500 or if
possible a way to connect a standard 32-pin PC floppy drive to it.
Is
that possible?
Thanks --
Alex
Jerry Heyman
You should check out eBay. There are many A1010 (Amiga 3.5" external
diskette drives) for sale there.
As for a standard PC Floppy, I think there's an issue with the
auto sensing that the Amiga uses to automatically mount a diskette
when inserted. Not sure that capability is available on a standard
PC floppy drive.
http://www.carrott.org/amiga/floppy.html
>
>
> Thanks --
>
>
> Alex
jerry
--
// Jerry Heyman | "Software is the difference between
// Amiga Forever :-) | hardware and reality"
\\ // hey...@acm.org |
\X/ http://www.hobbeshollow.com
Know1
"Alex" <sam...@gmail.com> wrote in message news:74a8783d-916a-425c...@c33g2000hsd.googlegroups.com...
It would be far easier just to buy one.
Here`s a list of compatible drives
if it were to be an internal(DF0) replacement.
http://www.freewebs.com/computolio/amiga_floppy_compatibility.html
For an external drive(DF1); you`d need to
be able to assemble the cable + circuit board.
Possible, but rather difficult.
Ryan P.
> on Tuesday 26 February 2008 4:42 pm, sam...@gmail.com (Alex) wrote:
>
>> Hello,
>>
>> I'm trying to find an external floppy drive for my Amiga 500 or if
>> possible a way to connect a standard 32-pin PC floppy drive to it.
>> Is that possible?
>
> You should check out eBay. There are many A1010 (Amiga 3.5" external
> diskette drives) for sale there.
>
> http://cgi.ebay.com/Commodore-Amiga-A1010-1010-external-floppy-drive_W0QQitemZ260214797599QQihZ016QQcategoryZ4598QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
>
>
> As for a standard PC Floppy, I think there's an issue with the
> auto sensing that the Amiga uses to automatically mount a diskette
> when inserted. Not sure that capability is available on a standard
> PC floppy drive.
.
I seem to recall that the auto sensing was a hardware tweak of
existing PC floppy hardware. The other issue is that PC drives can't
read Amiga formatted disks because Amiga drives physically use more
space which PC drive heads can't reach without modification. (Which is
why you get 880K from a formatted Amiga disk, and 760K from a PC disk).
With some tweaking, I think a PC floppy drive can COPY an Amiga disk,
but it can't actually read it.
orange
RDY signal, take a look at recent discussion on aorg:
http://www.amiga.org/modules/newbb/viewtopic.php?topic_id=43788&forum=8
4wd
The floppy drives used on the Amiga use the original defined floppy
interface standard - of course, when manufacturers of floppy drives
found that the relevant signals weren't required for PC use those
signals were removed to make the drive cheaper, (probably) - thus
another standard butchered in the name of cost.
The fact that the Amiga can get 880k on a floppy as opposed to the 720k
that PCs get is just a fact of using a different filesystem. The
standard 3.5" floppy drive is 80 tracks, (40/side), regardless of
whether it's used on an Amiga or PC.
> With some tweaking, I think a PC floppy drive can COPY an Amiga disk,
> but it can't actually read it.
With the correct interface circuit, (I made a couple years ago), any PC
compatible floppy drive will work as an Amiga floppy drive for both
ready _and_ writing, (either 3.5" or 5.25").
There is _one_ exception to this - the Amiga high-density floppy drives.
It's extremely difficult to get normal HD 3.5" floppy drives to run
reliably at 150RPM, (normal is 300RPM), required due to the hardware
design of the Paula chip, (ie. it can't keep up with the data rate
supplied by a high-density 3.5" floppy). The only other way to do it
would be to buffer the data from the drive and send at a lower rate to
the Amiga.
HD 3.5" floppy drives will, however, work reliably as a normal DD Amiga
floppy drive, (given the correct interface).
BTW, when you open an external Amiga floppy drive, the three, (IIRC),
74xx series chips you see are primarily there to send the correct ID
code to the Amiga when it powers up.
$0000 0000 - No drive present
$FFFF FFFF - Standard 3.5" DD floppy
$5555 5555 - 48 TPI DD/DS (This was the A1020, 5.25" external.)
$AAAA AAAA - IIRC, this was the code for the HD 3.5" floppy
To learn more, go to my page at http://4x4.hopto.org and download the
A500/A2000 TRM - pages 6-8 describe the interface.
Dave