worm.sz

        ORG    0
        BR    /START
N       DATA   14      ;SCROLLING VARIABLES
I       RES    1
CONT    DATA   0    
OLD     DATA   22      ;POSITION VARIABLES
LOOP    DATA   28
DIR     RES    1       ;CPY PARAMETER
BRKEY   DATA   1536    ;=BR/0
LDKEY   DATA   512     ;=LD/0
STAD    DATA   3597    ;=ST/(n+N-1)-LD/n
CPY     LD    /LDKEY   ;CPY FUNCTION
        ADD   /DIR     ;Address prep for LD and ST
        ST    /LDEX
        ADD   /STAD
        ST    /STEX
LDEX    RES    1       ;Store requested copy in
STEX    RES    1       ;new address
        LD    /BRKEY
        ADD   /LOOP
        ADD   /CONT
        ST    /BREX    
BREX    RES    1       ;Branch to loop begining
        LD    /N       ;Updates initial conditions
        DEC
START   ADD   /CONT    ;Stores modified CONT
        ST    /CONT    ;(starts at 0)
        LD    /N       ;I initial cond.
        ST    /I
        LD    /I       ;Loop begining
        DEC
        ST    /I
        LD    /OLD     ;Address calculations
        ADD   /I       ;for CPY
        ADD   /CONT
        ST    /DIR
        BR    /CPY     ;Function branch
        DATA   585     ;The loop ends by replacing
        RES    500     ;BR/CPY with the nexts loop's
        END            ;initial conditions