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Tag Archives: Disk drives
CBM Flux Studio: a few update videos
As I am pretty busy with my new job, I didn’t have a chance to blog about the most recent videos I published in my YouTube channel. I haven’t got time to comment on them today either, but here’s proof … Continue reading
Posted in Retrocomputing, Reverse Engineering, Technical
Tagged Commodore 64, Disk drives, FM, GCR, magnetic flux, preservation
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How to tell if a disk sector was overwritten by a CBM drive
The question about whether or not a disk sector was overwritten is relevant when assessing whether or not an original disk was modified, e.g. for saving a hi-score table. In fact, while researching the Vorpal disk loader used by California … Continue reading
Posted in Retrocomputing, Reverse Engineering, Technical
Tagged Commodore 64, Disk drives, FM, GCR, magnetic flux, preservation, sync, Vorpal
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Vorpal Duplicator Information decoded
I am still quite busy due to the fact I changed job this week, but I decided to share some of my Python material to manipulate low-level flux reversal data captured with e.g. KryoFlux. In fact, I had written a … Continue reading
Posted in Retrocomputing, Reverse Engineering, Technical
Tagged Commodore 64, Disk drives, FM, GCR, magnetic flux, sync, Vorpal
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Flux Studio: progress update
I chose to make a video to show a comprehensive list of “official” features currently available in Flux Studio 0.8: One thing that I should investigate is the actual structure and purpose of the unusual t/s 18/16 in later Vorpal … Continue reading
Posted in Retrocomputing, Reverse Engineering, Technical
Tagged Commodore 1571, Commodore 64, Disk drives, GCR, magnetic flux, sync, Vorpal
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One last look at later Vorpal disks
Inspired by the recent exchange with Mr. Laufwerk, I decided to share a few pictures that show how tracks are mutually aligned in a few later Vorpal disk images. None of the disk images I used were realigned: they show … Continue reading
Posted in Retrocomputing, Reverse Engineering, Technical
Tagged Commodore 1571, Commodore 64, Disk drives, GCR, sync
4 Comments
Vorpal disks: lead-in and trailing patterns
As the question was asked, here you find a visual representation of the lead-in and trailing patterns in original disks that use the later version of Vorpal: From left to right we see: trailing sequences lead-in sequences Worth noting: even … Continue reading
Posted in Retrocomputing, Reverse Engineering, Technical
Tagged Commodore 1571, Commodore 64, Disk drives, GCR, sync, Vorpal
9 Comments
Vorpal disks: perhaps the most reliable way to set write splice offsets
By now my readers should be familiar with the fact that one of the most severe risks involved in writing the data of a protected disk image back to a floppy disk consists in starting (and ending) the write operation … Continue reading
Posted in Retrocomputing, Reverse Engineering, Technical
Tagged Commodore 1541, Commodore 64, Disk drives, GCR, sync, Vorpal
4 Comments
Flux Studio: all Vorpal blocks can now be decoded
I finally also finished implementing the decoder for custom Vorpal blocks on track 18. There are four of these in California Games, used to load the main drive code into the drive RAM. Here’s the debug output from both Vorpal … Continue reading
Posted in Retrocomputing, Reverse Engineering, Technical
Tagged Commodore 1541, Commodore 64, Disk drives, GCR, sync, Vorpal
7 Comments
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 … Continue reading
Posted in Retrocomputing, Reverse Engineering, Technical
Tagged Commodore 1541, Commodore 64, Disk drives, GCR, sync, Vorpal
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Dissecting the Vorpal (later) disk protection – part 1
Update to this post: California Games does NOT load the main drive code from track 17.5 or 18.5 as previously stated. It loads from track 18.0 as the stepping instructions detailed below just step outward and then back onto track … Continue reading
Posted in Retrocomputing, Reverse Engineering, Technical
Tagged Commodore 1541, Commodore 64, Disk drives, GCR, sync, Vorpal
1 Comment
Luigi Di Fraia's e-Footsteps 