TI 83 Additional Accumulation All-overs

 27 July 02:18   

    In the antecedent program a characterization was written:

    

    text:

          .db Hello, World,0

    text: is a label. Labels are never called and consistently end with a colon. They mark a abode in a program. You can jump to a characterization by using jp labelname:

    

.NOLIST

    #define END .end

    #define end .end

    #define equ .equ

    #include ti83plus.inc

    .LIST

          .org 9D93h

          .db $BB,$6D

          jp clearscreen   ;here it is

          ld a,0

          ld (CURCOL),a

          ld a,0

          ld (CURROW),a

          ld hl,text

          B_CALL(_PutS)

          ret

    text:

          .db Text,0

    clearscreen:           ;and actuality it goes

          B_CALL(_ClrLCDFull)

          ret

    .end

    end

    (B_CALL(_ClrLCDFull) clears the screen.) The program aloft clears the awning but never displayes text. Why? Because jp clearscreen automatically all-overs to the characterization clearscreen and skips over all the argument affectation code.

    By the way, the being followed by the semicolon are comments: they are acclimated to explain the cipher and are abandoned by the compiler. (The compiler Interface' onMouseOver="tip('infobox1')" onMouseOut="untip()" target='_parent'> compiler is the program which converts the cipher you address to cipher a apparatus can read.)

    jr is a jumping apprenticeship agnate to jp, but with a few important differences. Its one byte abate (this may not assume like a lot, but it can add up); however, clashing jp (which can jump to any address), jr can alone jump to a characterization thats up to 127 bytes advanced or up to 128 bytes astern in your code. So, use jp if the characterization is far abroad but contrarily use jr. In fact, you may wish to consistently use jr, because if you abridge an absurdity will be alternate if the characterization is too distant.

    The jump in the aloft program could be replaced with jr:

    

.NOLIST

    #define END .end

    #define end .end

    #define equ .equ

    #include ti83plus.inc

    .LIST

          .org 9D93h

          .db $BB,$6D

          jr clearscreen      ;this saves space!

    Imagine if you wish to jump about and then go back. Use alarm and ret:

    

.NOLIST

    #define END .end

    #define end .end

    #define equ .equ

    #include ti83plus.inc

    .LIST

          .org 9D93h

          .db $BB,$6D

          alarm clearscreen   ;1. actuality it is

          ld a,0             ;4. to here

          ld (CURCOL),a

          ld a,0

          ld (CURROW),a

          ld hl,text

          B_CALL(_PutS)

          ret              ;5. and ends

    text:

          .db Text,0

    clearscreen:           ;2. actuality it goes

          B_CALL(_ClrLCDFull)

          ret              ;3. then it comes back

    .end

    end

    As you can see, the first ret (right afterwards the _ClrLCDFull) went aback to the alarm command. Then, the additional ret concluded the program. You can anticipate of your program as one big alarm routine, with the catastrophe ret traveling aback to the capital calculator. Warning: Calls baffle with stacks.

    These all-overs can be accumulated with cipher abstruse in after sections.