CommandBlock Pseudocode: Arbitrary-Precision Addition

ARBITRARY-PRECISION SIGNED-INTEGER ADDITION:
VARIABLES:
    null:       air
    char:       wool or stained_hardened_clay
    registers:  v0  #carry of prev op
                v1  #for t1
                v2  #for t2
                b0  #boolean result
                b1  #base
    pointers:   p1  #for t1
                p2  #for t2
                p3  #for t3
    tapes:      t1  #input 1
                t2  #input 2
                t3  #output

sys_reset:
    move p1 tape_start  # move p1 to start of tape
    move p2 tape_start  # move p2 to start of tape
    move p3 tape_start  # move p3 to start of tape
    $v0 = 0             # load 0 into $v0
    $v1 = 0             # load 0 into $v1
    $v2 = 0             # load 0 into $v2
    $b0 = 0             # load 0 into $b0

sys_write:
    write p3 $v1        # write $v1 on t3 at p3
    p3++                # move p3 to next char

sys_read:
    $b0 = 0             # load 0 into $b0, 0=failed reading
    $v1 = 0             # load 0 into $v1
    $v2 = 0             # load 0 into $v2

    test p1==char       # p1 pointing at a char
        $v1 = read p1   # read p1, store in v1
        $b0 = 1         # $b0 = found some input

    test p2==char       # p2 pointing at a char
        $v2 = read p2   # read p2, store in v2
        $b0 = 1         # $b0 = found some input

    wait()              # wait for read
    p1++                # move p1 to next char
    p2++                # move p2 to next char

fun_add:
    sys_read            # $v1 <- p1, $v2 <- p2, p1++, p2++, $b=0->failed
    wait()              # wait for read
    $v1 += $v0          # add $v1 and $v0, store in $v1
    wait()              # wait for tests

    test $b0 == 0       # reached end of t1 and t2
        test $v1 == 0   # no carry left over
            $b0 = 1     # $b0 = no carry left over
        wait()          # wait for previous test
        test $b0 == 0   # carry left over
            sys_write   # write carry
        wait()          # wait for sys_reset
        sys_reset       # reset p1,p2,p3,v0,v1,v2,b0
        END

    test $b0 == 1       # not reached end of t1 or t2
		$v0 = 0			# load 0 into $v0
        $v1 += $v2      # add $v1 and $v2, store in $v1
        wait()          # wait for add
        $v0 += $v1      # copy v1 into v0
        wait()          # wait for add
        $v0 /= $b1      # carry = $v0 / base
        $v1 %= $b1      # remainder of $v1 / base, store in $v1
        wait()          # wait for /= and %=
        sys_write       # write $v1 on t3 at p3, p3++
        wait()          # wait for write
        fun_add         # repeat fun_add