Cloning BOOT13, Pt.2

[Lyrical Nanoha <LyricalNanoha@dosius.net>]

http://www.dosius.net:8080/boot13u-prelim.a65.txt

This is the current source code for Boot13-PathoLogic.  It doesn't work.

The user interface - that is, everything up to and including this line

inpok1: and     #$07            ; remove high nibble

is usable even if the remainder of the core needs to be rewritten.  The 
data in bimage (which is page-aligned) is the 13-sector DISK.ROM.  I'm 
getting a heisenbug when trying to track down why this isn't working.

Okay, here's what the situation is after that AND is executed.

  * A contains the slot number to boot from. (1-7)
  * I need to decode the boot sector like the boot ROM does, and jump to 
the boot code at $0301.
  * Simply hacking the disk ROM to fall through instead of doing an RTS 
into the following byte doesn't work for some reason (timing?), so I can't 
try migrating that into the program. :(

-uso.