;; sum numbers from 1 to X

; zero everything
    and ADM, #0, A
; initialize counter
    mov A, #10
    add D, #0, A

;loop:
; set memory location
    mov A, #0
; add to memory location
    add M, M, D
; prepare jump address
    mov A, #3
; decrement counter
    dec.jne D, D
; set memory location again
; end
; I have no idea why, but my simulator
; either aborts too early (before state is displayed)
; or too late (when invalid ins. is already shown).
    mov A, #0
    mov A, #0
    mov A, #0
    hlt