G64 Extended format

[SLC]

Hi

I'm currently writing a small tool for converting a g64 to ascii and back, but I'm wondering about the extended header... it seems to have 16 bytes for each track, but what are those different values?

[IFW]

0: write splice position
4: write area size
8: bitcell size
12: track fill value
13: N/A
14: format code
15: format extension

[SLC]

Excellent. Thank you for prompt answer.

[ZrX]

[markusC64]

I've written another tool for the same purpose: https://github.com/markusC64/g64conv

Just the g64 with mastering information alias g64 extended format is missing.

Will your tool be available to the public?

[SLC]

I'll possibly release it when I've cleaned it up a bit and properly supported the extended format AND the normal one. As of now, the program works only with the extended format (mainly because that is what I needed it for ). But it seems your tool is already better than what I have, so you may be better off adding the missing extensions now that you know what they are But I'll keep you posted when I've finalized things a bit more.

[markusC64]

Well, if it seems to be convenient to you, you can patch my tool. It is GPLv3 licensed, so there is no problem.

Anyway, for the p64 conversion, there is a need for a documentation of the interpretation of those extensions and not only the name of of fields.

I'll add the extended g64 support to my tool when p64 conversion can benefit from it. But I'll accept merge requests for that support at any time.

[SLC]

I was wondering if I could ask a follow up question to this... exactly how is the bitcell size determined when dtc creates G64-files? Also, could I have a list of what the various values in Format code and Format extension represents?

Edit: So far I've drawn the following conclusions, and hoping that this can be verified and/or corrected and completed

Format codes:

1 : CBM GCR
2 : CBM DOS
3 : CBM EXT
4 : Microprose
5 : RapidLok
6 : Datasoft
7 : Vorpal
8 : V-Max

Format extensions: (so far full of holes, and I have yet to understand the need for both this and format codes)

2 : Cyan B
4 : RapidLok
12 : XEMAG

What information is dtc given by these two parameters that enables it to re-create the disk upon write?

[ZrX]

Most likely (peeking into DTC):

Format
0 - Unknown format
1 - GCR Data
2 - CBM DOS
3 - CBM DOS Extended
4 - MicroProse
5 - RapidLok
6 - Datasoft
7 - Vorpal
8 - V-MAX!
9 - Teque
10 - TDP
11 - Big Five
12 - OziSoft

Extension
0 - Unknown protection
1 - Datasoft with Weak bits
2 - CBM DOS with Cyan loader, Weak bits
3 - CBM DOS with Datasoft, Weak bits
4 - RapidLok Key
5 - Data Duplication
6 - Melbourne House
7 - Melbourne House, Weak bits
8 - PirateBusters v1.0
9 - PirateBusters v2.0, Track A
10 - PirateBusters v2.0, Track B
11 - PirateSlayer
12 - CBM DOS, XEMAG