[Freedos-user] USB/ASPI to DOS, 4K sectors.

[Bertho G. <y31...@ya...>]

Continuation of previous question, subj changed,  was: "Support for 4k byte sectors"

Leaving aside (Free)DOS kernel support for bigger HD sectors.

Reminder : the following - should fit on one line - is a schematic of what is expected to work :

Hard Disk -- USB (4K sectors) -- DOS with "usbaspi.sys" (ASPI manager) -- "didd1000.sys" (ASPI to DOS converter)

The ASPI to DOS converter is the part that has to adapted, or else redone from scratch. I mm using Novac's excellent DIDD1000.SYS as a reference, unfortunately as distributed that assumes 512 byte sectors for hard disks.

After some partial disassembling and study, it seems it is not an easy task to patch DIDD1000 *without access to source code*. The (non essential) int 13 implementation is relatively easy to fix, but the DOS interface (scan partition tables and install DOS volumes; execute DOS driver commands) is problematic, not the least because enlarging some buffer posited in the middle of the driver would offset all data and code situated after said buffer, both during the transient (installation) and permanent phases of the DOS driver's life...

Intellectual property and legality matters set apart°, would it be easier to make a new "ASPI to DOS, 4K aware converter" from scratch ? Or rather, are there usable bases for such an endeavor (free source code) ?

° It is my understanding, in vague terms, that most stringent "anti reverse engineering" laws allow for independent fixes and enhancements to IP protected code, but IANAL.


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