Flux Studio: progressing with the development while dissecting Vorpal

My current efforts with Flux Studio when it comes to Vorpal are twofold:

  • create a data decoder in order to check the integrity of G64 images (similarly to what TAPClean does for TAP images)
  • detect at which point in a track the original write operation started and realign data in a G64 image accordingly, so that it can be properly rewritten to a floppy disk (i.e. the writing does not start in the middle of a custom sector)

The data decoder is progressing nicely. What you see below is a comparison of how the first custom block in California Games is read in by the drive and decoded at the C64 side, and how the same process, with the same results, occurs in Flux Studio.

Flux Studio: Vorpal data decoder compared to VICE' monitor data by Luigi Di Fraia
Flux Studio: Vorpal data decoder compared to VICE’ monitor data

The second point, also referred to as write splice detection with KryoFlux tools, is pretty simple to achieve in principle and also quite simple to do in a visual tool such as Flux Studio.

Take California Games as example. The G64 that was provided to me by SLC does include write splice offsets generated by KryoFlux, so I can already use these to realign track data in Flux Studio. However, the one for track 27 is not right.

Before I code my own algorithm to automate the process, I added a manual alignment feature to tackle this issue:

Flux Studio: manual track alignment tool by Luigi Di Fraia
Flux Studio: manual track alignment tool

Using this tool I was able to generate a G64 that passes the checksum verification on every track when KryoFlux writes it back to disk and re-images the disk 🙂

Stay tuned for more!

About Luigi Di Fraia

I am a Senior DevOps Engineer so I get to work with the latest technologies and open-source software. However, in my private time I enjoy retro-computing.
This entry was posted in Retrocomputing, Reverse Engineering, Technical and tagged , , , , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s