G64 with mastering information?

3rd Party Software, Tools & Add-ons for KryoFlux
enigma
Posts: 4
Joined: Wed Sep 24, 2014 12:18 pm

G64 with mastering information?

Post by enigma » Tue Jan 29, 2019 1:00 pm

Hello,

I often image disks with Kryoflux that I get from various collectors. The disks are mostly from the C64.
I usually convert the raw streams to G64 with mastering information (-i22a) that I can checkout the content with DirMaster/Style or Vice.

For quite a few G64 images I noticed that there appear issues in various programs. A typical issue in Vice is that the directory preview shows garbage while doing a LOAD"$",8 works fine.

Also DirMaster shows garbage for the directory on some disks and C64-Archive rejects G64s stating they are invalid.

I contacted the authors with some example G64 files. The question came up, if there is some documentation of the G64 with mastering information format available?

It also seems that most programs are tested against Peter Rittwages (C64 Preservation Project) G64 archive. But there seem to be no general G64 image test suite that includes images with certain pecularities to consider.
I would like to suggest to collect such images for a test suite. My hope is that this would help to improve the G64 support in the software.

I have attached three G64 images that are problematic.

Best regards,
Michael
Attachments
g64_images.zip
(317.02 KiB) Downloaded 20 times

brightcaster
Posts: 175
Joined: Fri Nov 08, 2013 10:48 pm

Re: G64 with mastering information?

Post by brightcaster » Tue Jan 29, 2019 2:37 pm

I have no problems with the directories using vice (x64 2.4.9 GTK+ AMD64/x86_64) on linux!
Attachments
third.png
directory third disk
third.png (3.62 KiB) Viewed 494 times
second.png
directory second disk
second.png (3.63 KiB) Viewed 494 times
first.png
directory first disk
first.png (2.6 KiB) Viewed 494 times

brightcaster
Posts: 175
Joined: Fri Nov 08, 2013 10:48 pm

Re: G64 with mastering information?

Post by brightcaster » Tue Jan 29, 2019 2:51 pm

Okay, this is not a matter of the G64 but of control-codes in the disks name! If you list the directories content to the screen the listing gets confused by missinterpreting theese control-codes as long as you use the original c64 kernel. With speeddos or dolphindos (as I did) as kernel rom theese codes are ignored and everything lists fine...

So this is not G64 related! It happens on the original machine with the original disk! It was intended to behave this way I gues!

David

enigma
Posts: 4
Joined: Wed Sep 24, 2014 12:18 pm

Re: G64 with mastering information?

Post by enigma » Tue Jan 29, 2019 3:04 pm

That is what I wrote, that the images work in Vice emulation (and the disks with a real floppy).

However if you take a step back and look at common tools:


Screenshots from
Vice 3.3. r35896 (also in earlier Versions) Directory Preview and Dirmaster 3.1.1. for e.g. disk_0001.
disk0001_vice.png
disk0001_dirmaster.png
And C64-Archive says it is an invalid G64 file on import.

So while the G64s work the applications have problem with them. That is also why I was proposing some kind of G64 image test suite.

User avatar
mr.vince
Posts: 2109
Joined: Tue Oct 05, 2010 5:48 pm

Re: G64 with mastering information?

Post by mr.vince » Wed Jan 30, 2019 2:23 pm

These tools need updating.

brightcaster
Posts: 175
Joined: Fri Nov 08, 2013 10:48 pm

Re: G64 with mastering information?

Post by brightcaster » Wed Jan 30, 2019 7:04 pm

It was verry common to use theese so called PETSCII codes below $20 in the disknames or filenames to "hide" them. PETSCII Codes $00-$1F and $80-$9F are control codes and printing them will cause a change in screen layout or behavior, not an actual character displayed! If you look at the directory with a hex-editor you will recognize some of them on the samples you loaded up.

So theese weird directories are designed that way and not faulty! Kernels like dolphindos and speedos ignore them (as a feature) while listing a directory. Since the disk samples you uploaded are not copyprotected you may re-read them as d64-images and expirience the same behavoir.

The fileviewer in vice emulates this correctly as its emulating the original look and feel!

So this is nothing to worry about. This is happening with the original disk and machine, as it was designed to behave this way!

David

ZrX
Posts: 515
Joined: Tue Dec 06, 2011 9:09 pm

Re: G64 with mastering information?

Post by ZrX » Wed Jan 30, 2019 8:21 pm

The "problem" with Vice, as the devs checked out yesterday, is that disk viewer while opening a disk image doesn't really analyse the content and just assumes track 18 to be at the correct track.

User avatar
mr.vince
Posts: 2109
Joined: Tue Oct 05, 2010 5:48 pm

Re: G64 with mastering information?

Post by mr.vince » Thu Jan 31, 2019 3:46 pm

Hence my recommendation, to fix the tools, not the data (which is correct).

rcade
Posts: 118
Joined: Mon Nov 21, 2011 5:21 pm

Re: G64 with mastering information?

Post by rcade » Fri Feb 01, 2019 7:35 pm

Are we talking about disk images where there is some alignment problem and track 18 is not on track 18, but stepped off a half or whole track in one direction? That's a data problem, not a tool problem. I mean unless this is mastered this way on purpose with a drive that is out of alignment?
-
Pete Rittwage
C64 Preservation Project
http://c64preservation.com

Feltzkrone
Posts: 255
Joined: Sat Jun 18, 2011 8:03 pm

Re: G64 with mastering information?

Post by Feltzkrone » Sat Feb 02, 2019 2:37 pm

I can't check at the moment but if I recall correctly it could be important that the syncs end at a byte boundary so that the GCR data can be directly found and interpreted as expected. Also I think that I have seen some disks where the physical order of sectors does not match the logical one, so that e.g. sector 1 doesn't immediately follow sector 0. This could also break naive code for interpretation of track 18.

Edit: The first obvious finding is that none of the attached G64 disk images are index aligned.

Post Reply