Search found 35 matches

by keir
Sun Sep 02, 2012 9:17 am
Forum: Software Development
Topic: Linux users: What distro are you using?
Replies: 10
Views: 6289

Re: Linux users: What distro are you using?

Fedora latest (x86_64)
by keir
Mon Jun 18, 2012 8:38 pm
Forum: Software Development
Topic: All you always wanted to know about IPF
Replies: 86
Views: 35319

Re: All you always wanted to know about IPF

I think that I understand the info returned for sectors. I am still not 100% sure about gapsizemode value 0 (fixed size) http://info-coach.fr/atari/software/projects/_ipf/html/_caps_a_p_i_8h.html#aa471858b6ad1275ccd147495c22444ad for the write splice (attached analysis of back to the future - secto...
by keir
Mon Jun 18, 2012 8:17 pm
Forum: Software Development
Topic: All you always wanted to know about IPF
Replies: 86
Views: 35319

Re: All you always wanted to know about IPF

DTC always completely erases a track during writing. What does that means? As FD drives do not have erase head do you mean that a random signal is first written? Writing with no data provided on the write head? (should not do anything in this case as no flux transitions!) Writing to a track with no...
by keir
Wed Feb 08, 2012 11:49 pm
Forum: Software Development
Topic: All you always wanted to know about IPF
Replies: 86
Views: 35319

Re: All you always wanted to know about IPF

Yeah, a uniform-density track has to return 1000 for every entry in the timebuf, by definition. You have that figured out fine.

I think weak bit protection is quite rare. I've never analysed one myself.
by keir
Mon Jan 30, 2012 3:03 pm
Forum: Software Development
Topic: All you always wanted to know about IPF
Replies: 86
Views: 35319

Re: All you always wanted to know about IPF

Both. Capsdef.h: CapsImage.sigtype CapsImage.dentype CapsBlock.bt.sps.celltype In the released decoder sources, only the per-track dentype is actually connected to any 'moving parts'. The others may allow future extensions, but at the moment '2us cells' is all that's allowed, and is thus pretty muc...
by keir
Mon Jan 30, 2012 12:16 am
Forum: Software Development
Topic: All you always wanted to know about IPF
Replies: 86
Views: 35319

Re: All you always wanted to know about IPF

Now that I understand a little bit more the IPF format I have the following questions: 1. I do not see any timing information anywhere in the IPF file? For example the bit-width/clock speed of data. Therefore how do you indicate that the first n bytes of this sector have a 4µs width and the next m ...
by keir
Mon Jan 30, 2012 12:01 am
Forum: Software Development
Topic: All you always wanted to know about IPF
Replies: 86
Views: 35319

Re: All you always wanted to know about IPF

I think you have got the wrong offset for the start of the gap stream. If you started decoding from the immediately following byte (22 08 4E ...) then it would be a good reverse gap stream. Which is what you expect as Block->Flags=2, which indicates a reverse gap stream is present. EDIT: Also C0 is ...
by keir
Mon Jan 23, 2012 9:00 pm
Forum: Software Development
Topic: All you always wanted to know about IPF
Replies: 86
Views: 35319

Re: All you always wanted to know about IPF

Yes, I was looking at some Atari IPFs myself, so it was quickly obvious that my own source file needed fixing. I hope my informational text file is useful. I'm confident it's broadly accurate, it's effectively a reverse engineering of the decoder library, plus looking at some example IPFs and the bi...
by keir
Thu Jan 19, 2012 1:23 pm
Forum: Software Development
Topic: All you always wanted to know about IPF
Replies: 86
Views: 35319

Re: All you always wanted to know about IPF

Yes, it's easy to forget the differences between an emulator and a real floppy drive. For example, I wondered at first why the IPF decoder applies Copylock density changes from the start of the preceding block's gap. It was a hand meets forehead moment when I realised why my own Copylocked IPF image...
by keir
Thu Jan 19, 2012 12:39 pm
Forum: Software Development
Topic: All you always wanted to know about IPF
Replies: 86
Views: 35319

Re: All you always wanted to know about IPF

Sorry, I should have tried the latest DTC version before complaining -- my initial development was testing writes with Windows beta3. The just released Linux beta7 works fine, and I can read back and verify the write splice is definitely somewhere in the middle of the track gap. And of course a real...