Step 2: How much is too much?

Since the snake starts small and grows, we also need to keep track of how many snake dots there are on the screen at any time. So we'll create snakecount. Byte-sized is fine, since MAX_LENGTH is 256.

Snake.spin

VAR
    byte    snakex[MAX_LENGTH]
    byte    snakey[MAX_LENGTH]

    byte    snakedir
    byte    snakecount

PUB Main
    lcd.Start(gfx.Start)

Since we start with 1 pixel, we'll set snakecount to 1 at startup.

Snake.spin

    snakey[0] := 32
    snakedir := 1
    snakecount := 1

    repeat
        gfx.Clear

We're going to add a variable i. This one is just used for a repeat loop.

Snake.spin

    byte    snakedir
    byte    snakecount

    byte    i

PUB Main
    lcd.Start(gfx.Start)