Hovalaag Bug?

soln_6.vasm

; The documentation in sample.vasm states that "F=POS(A>>1) is true if and only if A was positive and even before the shift"
; This doesn't seem to be the case in v1.08. Even a negative even number seems to give a true value.

; Solution for problem 6.

get_input:
    A=IN1, C=0, B=1
    D=A
loop:
    F=ZERO(-A)
    JMPT out, F=ZERO(A&B)
    JMPF update_c
    A=A>>1, JMP loop

update_c:
    A=A>>1, DEC, JMP loop
    
out:
    A=C
    ; A=-A  ; -> Commenting/uncommenting this line doesn't make a difference. Both give the correct result.
    F=POS(A>>1), A=D
    JMPT even, W=A
    OUT1=W, JMP get_input

even:
    OUT2=W, JMP get_input