APPENDIX TWELVE



     bytes, although you need change key assignments only for a
     specific few. Use the ATASCII values when writing the table.

     Several values have specific meaning to the keyboard decoder
     on the XL:

     Dec/Hex         Use
     128/80          Not used; invalid combination
     129/81          Inverse output
     130/82          Upper/lowercase toggle
     131/83          CAPS lock
     132/84          CTRL key lock
     133/85          End of file (EOF)
     137/89          Keyboard click toggle
     138-141/8A-8D   Function keys F1-F4 (1200XL only) or:
                     cursor up (ATASCII 28; $1C)
                     cursor down (ATASCII 30; $1D)
                     cursor left (ATASCII 31; $1E)
                     cursor right (ATASCII 32; $1F)
     142/8E          Cursor home (upper-left screen corner)
     143/8F          Cursor to bottom-left corner
     144/90          Cursor to left margin (1200)
     145/91          Cursor to right margin (1200)

     You can't redefine BREAK, SHIFT, CTRL, or the console keys (nor
     the CTRL-function key assignments on the 1200XL). The 1200XL
     Addenda gives a Dvorak keyboard assignment easily written
     into memory, The system table address is returned to RAM on
     power-up or RESET.

128,129        80,8           1 LOMEM
     Points to 7676 ($$1DFC).

512-551        200-227        Interrupt vectors
     The locations of the vectors and their functions remain the
     same, but they now point to different locations in the OS
     memory:

     Vector      Hex         Label      Points to
     512,513     200,201     VDSLST     49358 ($C0CE)
     514,515     202,203     VPRCED     49357 ($C0CD)
     516,517     204,205     VINTER     49357 ($C0CD)
     518,519     206,207     VBREAK     49357 ($C0CD)
     520,521     208,209     VKEYBD     64537 ($FC19)
     522,523     20A,20B     VSERIN     6691 ($1A23)
     524,525     20C,20D     VSEROR     6630 ($19E6)
     526,527     20E,20F     VSEROC     60140 ($EAEC)
     528,529     210,211     VTIMR1     49357 ($C0CD)
     530,531     212,213     VTIMR2     49357 ($C0CD)