Game 0 Unit 13 of 15 1 hr learning time

Making It Move

Bring the title card to life. Animation is draw, wait, erase, move, repeat — built from a loop, PRINT AT, and a pause, with nothing new to learn. And in the flicker of it, you'll see exactly why the Spectrum's legends wrote their games in assembly.

87% of Meet BASIC

Everything the title card needs to move, you already have. Animation is just draw, wait, erase, move, and repeat — a FOR loop (Unit 7), PRINT AT (Unit 9), and a pause. No new keyword. The lesson is putting the pieces together.

Milestone 1 — a star crosses the screen

  10 BORDER 1
  20 PAPER 1
  30 INK 6
  40 CLS
  50 PRINT AT 8, 11; "MEET BASIC"
  60 PRINT AT 10, 7; "a Spectrum primer"
  70 FOR x = 0 TO 31
  80 PRINT AT 14, x; "*"
  90 PAUSE 6
 100 PRINT AT 14, x; " "
 110 NEXT x
 120 GO TO 70

The loop is the whole trick. Each pass: PRINT AT 14, x; "*" draws the star, PAUSE 6 holds it for a moment so the eye can see it, then PRINT AT 14, x; " " erases it before x moves on. Line 120's GO TO 70 runs the whole sweep again, so the star tracks across the screen, over and over:

The title card, alive: a star tracks across, drawn and erased one cell at a time. That's all movement is — redrawing in a loop.

The title card now has everything: a place, a palette, a voice, and motion. You've built a small splash screen — the kind every game opens with — out of the pieces from the last twelve units.

The flicker — and the door it opens

Watch the star closely. It doesn't glide; it blinks along, a little rough, a little slow. That's not a mistake in your program — it's BASIC showing its limit. Drawing and erasing with PRINT AT, a pause in between, is the fastest BASIC can move a thing, and the eye catches every step.

This is the honest reason the Spectrum's legends — Manic Miner, Knight Lore, Cybernoid — wrote their games in assembly, not BASIC. Smooth, flicker-free movement needs to talk to the screen directly, faster than any BASIC keyword can. You've just felt, in your own splash screen, the exact wall they hit — and the reason the assembly track exists. When you're ready for motion that doesn't blink, that's where it lives.

When it doesn't work

  • The star left a trail. You drew without erasing. Every "draw" needs a matching "erase" at the old position before moving.
  • It moved too fast to see, or not at all. Tune the PAUSE. Bigger pauses slow it down; PAUSE 0 waits for a keypress instead.
  • It never stops. GO TO 70 loops forever by design — press BREAK (Caps Shift and Space) to stop it, or remove line 120 to cross once.

Before and after

You started with a still title card and finished with a moving one — and learned that animation is nothing more than draw, wait, erase, move, repeat, built from loops and PRINT AT you already knew. The idea underneath: movement is redrawing in a loop; in BASIC it flickers, and that flicker is the doorway to assembly.

Try this

  • Bounce it. When x reaches the edge, flip its direction with an IF (Unit 6) so the star travels back the other way.
  • Move it diagonally. Change the row as well as the column each pass.
  • Two stars. Animate a second one at a different row — and watch the flicker double.

What you've learnt

  • Animation is draw, wait, erase, move, repeat — no new keyword, just composition.
  • A PAUSE controls the speed; erasing the old position stops trails.
  • GO TO makes the movement loop, the game-loop shape made visible.
  • BASIC movement flickers — the honest limit that the assembly track is built to pass.

What's next

Your splash screen is complete — and you've met every feature the games will use. Two units left, both about keeping your work safe and sound. In Unit 14 we save a program so it survives the machine switching off.