Option 4: vector display. The bot becomes a glowing wireframe, drawn by an electron beam like 1979–82 arcade screens. Switch machines below.

**No pixels.**
Vector monitors steered one electron beam around the screen like a pen. They drew only lines. The rest of the screen stayed truly black.

**Tap "Show the beam."**
Time freezes and the scene redraws line by line with a bright beam head. That's exactly how the hardware worked, about 40 times a second.

**The bot is now a 3D wireframe.**
It has 5 latitude rings, 6 meridians, and eyes projected onto the sphere, so they curve and turn with it.

**Eyes are nested outlines.**
Vector hardware couldn't fill shapes, so artists drew 3 shrinking outlines to fake solid eyes.

**Persistence is phosphor glow.**
The screen coating kept glowing after the beam left. Raise the slider for long ghost trails. Lower it for a crisp, flickery image.

**The jitter is real history.**
Analog beam deflection wobbled with heat and voltage, which gave vector games their "alive" shimmer.

**Hidden lines stayed visible.**
Hiding back-facing lines cost too much processing, so Battlezone showed full see-through wireframes. The dimming option is a modern compromise.

**Complexity cost time, not memory.**
More lines meant a longer beam trip. Too many lines made the whole image flicker. Wireframe complexity had a time budget.

**The Vectrex screen was portrait.**
Each game shipped with its own tinted overlay, painted with the HUD (heads-up display) and colour zones.

**Raster vs vector**
```
RASTER (TV) VECTOR (Asteroids) →→→→→→→→→→ row 1 beam: A ──▶ B →→→→→→→→→→ row 2 │ →→→→→→→→→→ row 3 C ◀────── ┘ (every pixel, every frame) (only the lines, in draw order)
```

**One frame's display list**
```
[scene lines] → [latitudes ×5] → [meridians ×6] → [eye outlines ×6] each item: {x1,y1,x2,y2, colour, intensity} intensity = 0.2 if behind the sphere, else 1.0
```

**How the glow is faked**
```
pass 1: wide line (3.5px), 35% alpha, blur 10 ← halo pass 2: thin line (1.1px), 100% alpha ← hot core blend: "lighter" (overlapping light adds up, like real beams)
```

**Critical thinking:**
vector screens drew perfect diagonal lines while raster screens showed jagged steps. Why did raster still win completely? Price, colour, fill, or manufacturing scale?

**Lateral thinking:**
laser light shows, pen plotters, oscilloscope music and CNC (computer numerical control) machines all "draw" with one moving point. Could your bot be performed by a laser show or cut by a CNC machine using the same display list?

**First principles:**
if the beam can only be in one place at a time, what fixes the maximum complexity of any vector image? Could you work out the trade-off between line count and flicker from scratch?

- How do real oscilloscope music visuals work?
- Can this export as SVG for a pen plotter?
- What would a modern vector-style game look like?