VAPI ATX Enhanced Density support

[ijor]

This is a preliminary/experimental simple enhancement to the ATX specification to add support for Medium/Enhanced density images.

 

Attached is a brief documentation including the updated ATXFILE.H file.

 

Attached also is a modified Altirra to support this enhancement. Executables and the modified source (just a single file) are included. It is a quick temporary patch just for the purposes to run the images. Timing is probably not accurate for enhanced density images.

 

A sample enhanced density ATX image is included as well. It is just a DOS 2.5 formatted disk. We already have a small collection of original copy protected images in enhanced density, mostly European. But at this preliminary stage I would try to avoid distributing images just in case we decide to introduce some changes that would render those images incompatible with the final specification. Developers that would like some of these images for testing please contact me and I'll provide them.

 

 

Vapi-EnhDens.zip

Altirra-2.99-t8-AtxMedDens.zip

[Farb]

This is a preliminary/experimental simple enhancement to the ATX specification to add support for Medium/Enhanced density images.

 

Attached is a brief documentation including the updated ATXFILE.H file.

 

Attached also is a modified Altirra to support this enhancement. Executables and the modified source (just a single file) are included. It is a quick temporary patch just for the purposes to run the images. Timing is probably not accurate for enhanced density images.

 

A sample enhanced density ATX image is included as well. It is just a DOS 2.5 formatted disk. We already have a small collection of original copy protected images in enhanced density, mostly European. But at this preliminary stage I would try to avoid distributing images just in case we decide to introduce some changes that would render those images incompatible with the final specification. Developers that would like some of these images for testing please contact me and I'll provide them.

 

 

This is great news! Thanks for your hard work on this, Ijor!

 

Sent from my Pixel XL using Tapatalk

[ijor]

This is a small utility that will post process ATX images produced by Phaeron's a8rawconv with enhanced density disks. a8rawconv can decode enhanced density dumps correctly already. But the ATX image produced is not marked as enhanced density and then it won't work. The utility just corrects that.

 

Note that a8rawconv, written well before we added support for ATX images with enh density, will complain and warn you that ATX doesn't support MFM disks. Just ignore the warning. Note also that it will not issue a warning if there are bad sectors with physical sector number not valid for single density.

 

Source and executable are provided.

 

AtxMfmFix.zip