Catweasel Experts out there???

From: Curt Vendel <curt_at_atarimuseum.com>
Date: Sat Jan 24 20:38:50 2004

I just want to do a catdir and catcopy of the disks I have and copy the
contents to my local PC hard disk. I have a bunch of C64(5.25) ,
Amiga 800's(3.5) and Apple ][ disks (5.25)

Occassionally it'll read a C64 disk, no luck with the others.


Curt


Jim Battle wrote:

> Fred Cisin wrote:
>
>> Multiple choice:
>> "It can read xxxx disks" means:
>>
> ...
>
>>
>> B. It can read the physical disk, and has software that will
>> permit making an exact duplicate of the disk and/or creating
>> a file that contains an image used for replicating the disk.
>
> ...
>
>> The Cat Weasel appears to be able to do A, C, and maybe B.
>
>
> Actually, I'm mucking with a catweasel card right now.
>
> I took Tim Mann's code as a starting point and I'm going from there.
> I don't have any use for his decoding routines nor of making virtual
> disk images since my needs are different. However, I can't imagine
> how many hours of work he saved me by having routines that locate the
> card in PCI space. Also, his "trackhist" program provided some very
> useful subroutines. With the help of Tim's code, it took me less time
> to modify/write the code to decode the disk format than it did to rig
> up the 34-pin to 50-pin ribbon cable adapter.
>
> Anyway, I can provide an example disk format where the catweasel, as
> it stands, can't write the disk image, at least not without some
> dodgey trial & error (try to write a track, read it back and if it is
> mucked up, try and adjust the write timing for the next attempt. Even
> then, there is a lot of luck involved).
>
> Hard sectored disks are a problem for the catweasel to write. There
> is a function to write from index mark to index mark, except the
> catweasel assumes there is just a single index mark per revolution.
> Thus, you can write one sector, but you can't even reliably tell it
> which sector you want -- it just starts at the next index hole that
> appears. Perhaps under DOS you can disable interrupts and figure out
> via polling when sector N is about to appear and use index-to-index
> write mode. Even this doesn't suffice for the disk format used by the
> Processor Tech Helios system. It ignored every other sector mark so
> that effectively there were 16 256B sectors instead of 32 128B
> sectors. Further, blocks of data could be larger than 256B -- they
> simply spanned more than one sector. Thus, this mode is useless for
> that scheme.
>
> You can do a write where you specify "wait for an index hole, then
> write this sequence of transitions". The problem is that due to speed
> variations you can't say that index 5 is going to come exactly (166
> 2/3 ms / 32) after index 4. That is where you could try to write the
> whole track, then read everything back to see if you succeeded and if
> not, adjust the clock pulses wider or shorter to make things line up.
> Oh yeah, in this mode I think it doesn't wait for an index hole, it
> just goes whenever you tell it to, so good luck trying to get the data
> to line up with the index marks at all.
>
> As it turns out, now that I have the catweasel set up and running,
> there are three disk formats that I would personally find useful to be
> able to decode -- 8" Helios, 8" Wang 2200, and 5.25" Northstar. Guess
> what -- all three are hard sectored formats. Luckily, I'm really only
> looking to use it to archive virtual disk images, not to create new
> disks.
>
>

-- 
Curt Vendel & Karl Morris
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Received on Sat Jan 24 2004 - 20:38:50 GMT

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