USB Universal Floppy Disk controller

[Jim Battle]

Dwight K. Elvey wrote:
>>From: "Jules Richardson" <julesrichardsonuk at yahoo.co.uk>
...
>>What about cost? (irrespective of how the device physically connects to
>>the host machine)
>>
>>I forsee four goals to make it useful:
>>
>> o  Cheap
> 
> Hi
>  When one considers how much hardware one saves over a PIC solution,
> the DSP is cheap. They are in the $10 range.

Catweasel: $90-ish.  That is its disadvantage, but it offers a lot of 
convenience that a $10 DSP (OK, plus $10 in random analog bits, plus $10 
worth of sockets, and $xxx worth of time wirewrapping, etc).

>> o  Simple to build by anyone with a few electronics skills.
> 
>  A little tough here. 50 mil spaces surface mount. Some soldering
> skills required.

Catweasel wins this one hands down.  Just plug it in.

>> o  Open 'source' (all schematics etc. available)
> 
>  No issue here.

Except that it doesn't exist.  A hypothetical thing has any advantage 
that you wish to confer on it.

The catweasel design isn't open source, but I believe just about all the 
drivers are.

>> o  Easy / quick connectivity
> 
>  Although, most computers come with a parallel port, using
> the port on a newer XP for other than normal purposes may be a pain.

There are a number of drivers for linux/amiga/others that exist, and the 
driver for windows is coming along.  Someone else has already suffered 
the pain for us.

My own desire that motivated me to buy a catweasel was to collect and 
archive information.  The fact that the collection was done on a 
"modern" machine (there are isa and pci versions of the card) doesn't 
bother me at all.

>>Catweasel seems to lose out on 1, 3, and 4 - and 2 isn't relevant in its
>>case. Can't comment on how nice its software API is as I haven't looked
>>at it yet, but doubtless a bunch of us on this list could come up with
>>something that'd cater for all tastes (plus the really low-level
>>software would all be open source anyway!)

#2 isn't relevant -- what do you mean?  Sure, some people want to tinker 
with HW for the sake of tinkering with HW.  I have no fear of 
electronics but with my limited time, I get more satisfaction in other 
activities.  I'd rather spend a few $$ and save hours of effort 
collecting, building, troubleshooting so that I have time to do those 
other things.  I suspect that I'm in the majority otherwise this project 
would have been done already.

Even the lowest level software of the catweasel is open source.  So 
there is no advantage in this respect for the putative design.

>>Personally I'm not a fan of a USB version though; I'd rather have
>>parallel as pretty much any machine has a parallel port - USB limits me
>>to newer PCs and Macs (plus software interfacing *might* be harder). 
>>
>>Priorities seem to me to be (highest first):
>>
>> o  Reading disks
> 
>  Should be easy.
> 
>> o  Writing back a disk image
> 
>  I see only minor issues here ( pre-comp )
> 
>> o  Decoding disk data on host machine
> 
>  Just requires some one to do it.

These last three itmes were the main sticking point for a number of 
people.  The catweasel should be able to handle just about any format; 
it is "just" a simple matter of software yet to be written.  Yet it 
hasn't been done for many formats.

>> o  Modifying disk data on host machine, re-encoding back to floppy
> 
>  If one can do the above, this one comes along, almost
> for free.

The MK3 and earlier catweasels were deficient in their ability to write 
hard sectored disks efficiently, but MK4 should fix that.  At the HW 
level read and writing are both simple; writing the flux pattern in 
software is easier than decoding it.

Reading through a lot of the postings on this thread makes me think of 
somebody complaining that "linux is too big, bloated, and complicated, 
and redhat charges for their version too.  let's write our own version 
that will be lean and mean and available to all for free."  Thinking 
about the design is fun and the one who actually does it will have some 
rewards implementing it, but for most people, the already available 
solution will be superior to the proposed design even if it is ever 
done.  Spending $60 more for a finished, professionally done board might 
be a showstopper for some people, but futzing with the building your own 
  will preclude a great many more.