APPENDIX ELEVEN



      48  FF FF FF FF FF FF FF 00
      56  7F FF FF FF FF FF FF FF
      64  FF FF FF FF FF FF FF FF
      72  FF FF FF FF FF FF FF FF
      80  FF FF FF FF FF FF FF FF
      88  FF FF FF FF FF FF FF FF
      96  FF FF FF FF 00 00 00 00
     104  00 00 00 00 00 00 00 00
     112  00 00 00 00 00 00 00 00
     120  00 00 00 00 00 00 00 00

     The VTOC is the leftmost bit ot byte 55 ($37), and the directory
     sectors are the remainder of the byte plus the leftmost bit of
     byte 56 ($38). The leftmost four bits of byte 10 ($0A) are the boot
     sectors, and the remainder of the bytes up to and including the
     leftmost seven bits of byte 24 ($18) are in use by DOS and DUP.
     Remember that the last three bytes in the VTOC and directory
     are not status bytes.

     Disk directories and the VTOC (as well as many other disk mys-
     teries and delights) are explained in detail in Bill Wilkinson's
     Inside Atari DOS from COMPUTE! Books, and are somewhat dis-
     cussed in Atari Software Protection Techniques by George Mor-
     rison (Alpha Systems, 1983).

4856           12F8           ....
     Should read drive type, not tape.

5446,5450      1546,154A      ....
     LSB and MSB of the address the warm start routine places in 10
     and 11 (DOSVEC). POKE your RESET handler routine address
     here to always load it back into DOSVEC when RESET is
     pressed. Point to 6047 ($179F); a USR call to 6047 loads DUP and
     sends you to the DOS menu.

5576           15C8           ....
     You can run some machine language programs from within
     BASIC by typing OPEN #1,4,0, "D:filename" then
     X=USR(5576). CLOSE the channel afterward if you return to
     BASIC.

40960          A000           ....
     A USR here will cold start the BASIC cartridge. If you're handy
     with machine code, you can add commands to BASIC by trap-
     ping the keystrokes before they get passed on to the editor.
     Charles Brannon describes how to do this (with a good pro-
     gram of commands) in COMPUTE!'s Third Book of Atari.