PDI, the new MSX FILE FORMAT for Protected Disks is Finally Created

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Van hit9918

Prophet (2932)

afbeelding van hit9918

11-10-2015, 00:09

@wouter_ , there was that demo playing music from diskette that doesnt work on emu,
I wonder what may be the reason?

When one does step to next track, this takes the same milliseconds as the usual step rate?
When disk formatting makes a step, the next track ends up shifted 1/10 sector later?
Does maybe the dirasdisk or the DSK parser lack this shift and then the player misses a revolution?

the amiga needs it all coded on a lower level, maybe there is an inspiration in there
things at keyword "DSKRDY"

"after writing, 1.3 milliseconds must pass before switching disk side".
is this maybe independant of controller, the general law of drives? some capacitor is still swinging, and flipping to the other head would randombly corrupt things?
I imagine a WD controllers answer to this would be to just apply the same delay as is used for stepping.
But this would mean a headswitch is as slow as a step, a doublesided as fast as a singlesided?

"settle time" after stepping is mentioned.
maybe after doing a step, that head is still vibrating, wait a bit.
I guess the WD would just use the same delay as used when stepping across multiple tracks.

I remember my hdb-50 head started to make scary sounds when using phillips MSX DOS diskette.
now I think that was headmove speed up much.
maybe in far stepping one can use the little value, but the last step to track in question better goes with the big value for head setteling?

in portar.txt I read about an E bit making "15ms delay". about what is it? head settle time, headswitch time? :)

well, trying to search things :)
I feel when the emu does all the things within one track, there cant be missing much to make the music demo going.
I forgot its name, I think manuel told me.

Van ricbit

Champion (438)

afbeelding van ricbit

11-10-2015, 00:45

cbsfox wrote:

I will just release DSKPRO 9.0 with PDI support and let people decide if it is good or not.

Of course it's going to be good. We all thrust in you.

Van cbsfox

Champion (429)

afbeelding van cbsfox

11-10-2015, 00:46

Sure, you all do...

Van Jorito

Mr. Ambassadors (1790)

afbeelding van Jorito

11-10-2015, 10:51

Okay kids, keep the tone friendly here or we'll have to lock the topic. Thank you.

Van wouter_

Hero (522)

afbeelding van wouter_

11-10-2015, 11:19

cbsfox wrote:

By the way, why don't you choose another thread ....
... Thanks for your "great" support and lack of intelligence.

So yet again, what I'm saying does not stroke with your view and because of that I 'lack intelligence' and should go away?

This topic is about the PDI file format. My last two posts used technical arguments to demonstrate why I believe PDI (v1 or v2) is not the best format in the world. You may not like it but IMHO it is very much on topic. Arguably my last post was not the most friendly one, I apologize for that.

cbsfox wrote:

What is funny is that you are here in my thread ...

I wasn't aware you owned this thread and that we're only allowed to say things you agree with.
Before you edited your post you referred to DMK as 'my' format. I'm glad you corrected that mistake. But still you touched an important subject. When I needed a disk format for openMSX to store protected disks, I didn't invent my own format. Instead I did some research and evaluated several existing formats. In the end I settled on DMK, not because I think it's the best format in the world, but because I think it's the simplest format that satisfies all the requirements. If someday we find a case were DMK is inadequate I'd be happy to swap it for some other format. My research also taught me quite a few things about floppy disks that I didn't know before. To anyone interested in low level disk stuff I can recommend doing to same.

But I see you don't like DMK. I often refer to DMK in my examples because it's the format I know best. If you prefer to instead compare PDI to other formats like MFI, SCP, DFI, JV3, XSA or whatever, I'd be happy to do that as well.

I regret that in my last post I resorted to making claims without backing them up. So let's fix that and bring this post back on topic. I claimed PDI lacked one other ingredient before it can represent all Sunrise disks. @cbsfox: I understand you might not be interested in the following, but other people reading this thread may be curious.

The missing piece is the length of the track.
* A 3.5" DD disk does not always exactly rotate at 300rpm, and the data rate while formatting is not always exactly 300kbps, so the length of a raw track is not always exactly 6250 bytes.
* Disks have something called an 'index hole', disk controllers use this marker to synchronize whole track operations on (e.g. always start/stop read/write track commands near the same position in the track). Tracks are circular so they have no strict begin and end, but it's convenient to measure the position of e.g. a sector in a track starting from the index hole. Having a fixed reference position also allows to align the different tracks in the full disk, so it becomes possible to play with inter-track sector ordering, hit9918's last post touches this subject.
* At least some of the Sunrise disks I've analysed have a sector that wraps from the 'end' of a track back to the 'beginning'. When accessing the disk on a sector level there's nothing special about this situation. The position of the index hole happens to fall in the middle of the data, but that's irrelevant for sector commands. However when describing the disk on a track level it does become important that the length of the virtual track is the same as the real track, otherwise the wrapping behaviour is different.

Van wouter_

Hero (522)

afbeelding van wouter_

11-10-2015, 11:29

hit9918 wrote:

...Does maybe the dirasdisk or the DSK parser lack this shift and then the player misses a revolution?...

I don't want to hijack cbsfox' thread, so I'll be brief.
Even when using dirasdsk openmsx emulates rotational and seek delay. Though when using a high level feature like dirasdsk you do not have guarantees about the order of sector allocation in the FAT filesystem. Maybe this could be (part of) the explanation?
Maybe we should discuss this in more detail elsewhere.

Van cbsfox

Champion (429)

afbeelding van cbsfox

11-10-2015, 23:14

ok, Wouter, I will not argue with you again just because I don't like your attitude that I explained to you in the emais..
But ok, you don't like me so that's life.

And for the last time: I DO WHAT I WANT IN MY TOOL. DSK-PRO will support PDI as it's better for it.
Is that clear? Thanks GOD. Choose another thread that talks about your lovely DMK file format that has tons of MSX tools that support it.
And for the last time: DSK-PRO will never copy every copy protection. Maybe it can copy others in the future.

And let DSK-PRO works with PDI. And we will see what people think when they try it.

Marcos Daniel

Van Grauw

Ascended (10768)

afbeelding van Grauw

11-10-2015, 23:23

So PDI serves a specific purpose, and it will work great to copy disk protection schemes which DSK-PRO supports, but it will not be suitable as a generic copy protected disk file format. That’s good to know, now we know which file format is best to pick for archival purposes. That’s the information I was interested in.

Van hbarcellos

Hero (645)

afbeelding van hbarcellos

12-10-2015, 00:27

Well, let's change subjects shall we? Jorito already warned all of us.

Do you guys remember the lovely msx retrocrap game competition?
Among others, this creative masterpiece from Vampier was born:

Maybe it's time for MSX RetroCrap APPS/TOOLS competition???

Van flyguille

Prophet (3031)

afbeelding van flyguille

12-10-2015, 00:54

This thread brings to me some remembers, how I was asking everyone to jump in the "bandwagon" of MNBIOS like a crazy newbie in the international scene, telling it is great!, it is almost finish, I just needs to fix hardware models incompatibilities, and blah blah blah, it not was intended as vaporware, because I was bling of what a true multitasking system really needs in its internals, so for me, it was THE BEST. Until, someone got interest, review the programmers manual, and asked me, where is the message pipes service?, what?, everybody, FACEPALM!.

Now that I know everything about that, it is late, there is symbios, so, not needed to reinvent the wheel.

With all my respect, I think this guy is falling the same error, he is reinventing the wheel, just because is his "son" development. And by the way, I am a latin Americam user (Arg.), not an european, nothing personal.

Sometime, we dedicated too much time to a development, we emotionally loved it, and as any father we say it is the best, it is the product of our inteligence and it show how inteligent we are, the owner already jumps in his bandwagon, and that is when we start making errors, like skipping the field investigation about, is there already a good standard for that?, field investigation.

I can't throw the first stone here, because I know, that almost one time, everyone in differents matters had that moment on presenting his work as the best, being super proud. Later to see, after the blind stage, to see that it wasn't, that it requires a lot of more work, and that maybe the bandwagon don't get full.

I learned that in the hard way.

Just my 2 cents.

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