boot sector Help!

A sector on an Apple II floppy is only 256 bytes, even 3.5" floppies.

Exactly the boot sector is sector 0 track 0 with 256 bytes but... in your case you must write sector 0 with the first byte= the number of sectors to load. Normaly if you look a standard disk you'll see 01, so  you write 04 (if  code is less than 1024 bytes and write sectors 0,1,2,3  with your datas

Warning if your boot is exactly 1024 bytes... you must use 5 sectors and write 05  as first byte. Let me know if it's ok for you

A small precision : As you use the first  byte to setup the number of sectors to load ,  don't forget that you must assemble your code at ORG $801...  because the  Bootstrap in ROM givehand to  you with a JMP $801

HZA wrote:

Exactly the boot sector is sector 0 track 0 with 256 bytes but... in your case you must write sector 0 with the first byte= the number of sectors to load. Normaly if you look a standard disk you'll see 01, so  you write 04 (if  code is less than 1024 bytes and write sectors 0,1,2,3  with your datas

Warning if your boot is exactly 1024 bytes... you must use 5 sectors and wri

That's really interesting!  All these years and I never knew about that!  Or maybe I totally forgot long ago...  but good thing to know.  It could come in handy some day.