Frank Durda IV wrote a bit about the format; see
https://groups.google.com/forum/m/#!search/Trsdos$20ii$2027th$20sector$20disk$20change/comp.sys.tandy/0W_J2aNRpEI
When you say "TRSDOSII" do you mean "TRSDOS for Model II" or do you mean "TRSDOS-II" which means TRSDOS 4.x for Model II?
In both cases, you have odd formatting with mixed density and mixed sector sizes. You might have to hand-hack the HFE file to get it to work.
To distil Frank's information a bit:
For TRSDOS 2.x for Model II, you need 27 sectors per track, 256 bytes per sector, for all tracks except track 0 on bootable disks. TRSDOS-II 4.x uses 16 sectors per track, 512 byte sectors, except track 0 on bootable disks. As I recall, for double-sided you count two tracks per cylinder, one track per side.
The 27th sector on each track was apparently used for disk change detection and held no usable data (this is according to Frank).
Hope this helps; I don't have my 12 set up yet, but I do have the HxC for it, and will be able to directly check once I have it operational.
