Bernd Böckmann

> The BPB field for hidden sectors is chiefly for boot sector loaders. And they need it to be relative to the disk unit, not an extended partition. MS-DOS may...

Regarding UDSC_INT13EXT I found no evidence that this is actually used except of setting it on drive enumeration. UDSC_INT13BITS is currently used as a one-bit flag to indicate, if ext...

I removed UDSC_INT13EXT and UDSC_INT13BITS via [99765bd](https://github.com/SvarDOS/edrdos/commit/99765bd4c9ec9e035f1bd2af191c35d440c99383).

Todo (first educated guess): - adjust UDSC_TIMER low and high word (corresponding to offset 47h and 49h of DOS 6.22 UPB but shifted because EBPBs) - make UDSC having the...

This seems to contain a bug: https://github.com/SvarDOS/edrdos/blob/b328744eb2f86d597bda90029565acc0ac5e078b/drbio/disk.asm#L700-L702 Because UDSC_BPB_LENGTH is 41 and not 53. So the signature is not checked. I will adjust UDSC_BPB_LENGTH 53 and adjust the UDSC structure...

> Wait a moment, is this actually supposed to read a FAT32 EBPBN though? Shouldn't it rather be OLD_UDSC_BPB_LENGTH? I don't see this dispatching based on FAT12/FAT16 vs FAT32. Because...

> > > Wait a moment, is this actually supposed to read a FAT32 EBPBN though? Shouldn't it rather be OLD_UDSC_BPB_LENGTH? I don't see this dispatching based on FAT12/FAT16 vs...

check for FAT32 is now added to dd medchk via e1d3461.

Nice! Does the implementation of LBA unlock the use of larger partitions, or must other areas of the DOS 4 code be modified to achieve this? While skimming over DOS...

FAT32 would be very much work (the effort put into the EDR kernel by Udo proves that). UMA and HMA probably too, at least for the brain. Now that Microsoft...