Hex Display

Four bits in, one glowing hex digit out — watch binary become a number. A plain-English guide to components from TorchAnvil.

The Hex Display takes four wires and shows you what number they spell. Each input is one binary place value — 8s on top, then 4s, 2s, and 1s on the bottom — and the display renders the total as a single hexadecimal digit, 0 through F, on a classic seven-segment face.

How to read it

Add up the place values of the inputs that are on:

8s	4s	2s	1s	Value	Shows
0	0	0	0	0	0
0	1	0	1	5	5
1	0	0	1	9	9
1	0	1	1	11	b
1	1	1	1	15	F

Ten through fifteen show as letters — that's the "hex" part. The display uses the standard seven-segment letterforms A b C d E F: lowercase b and d, because an uppercase B would look exactly like an 8, and an uppercase D exactly like a 0.

Why it matters

Once your circuits start carrying multi-bit values — a counter, an adder, a register — reading four separate lamps and doing the mental math gets old fast. A hex display turns a 4-bit bus into something you can read at a glance. It's the difference between debugging with 1011 and debugging with b.

Four bits per digit is also exactly why hexadecimal exists: one hex digit is one nibble. Chain displays side by side and you can read any width of bus, four bits at a time.

In redstone

Seven-segment displays are a rite of passage in computational redstone — a wall of redstone lamps shaped like an 8, with decoding logic that turns a 4-bit input into segment on/off signals. Builds vary from pure gate logic to compact signal-strength tricks with comparators. The TorchAnvil component gives you the behavior so you can design the rest of your circuit first, then tackle the in-game display build once the logic works.

Gotchas

• Bit order matters. The top input is the most significant bit (8s), the bottom is the least (1s). Wire them upside down and 1 reads as 8.
• All inputs off shows 0, not a blank face — zero is a real number.
• It's a display, not a converter: there are no outputs, so nothing can be wired from it. To feed a value onward, tap the same four wires that feed the display.

Try it

The demo on the right wires four levers to the display, labelled with their place values. Flip the 8s and the 1s levers on and you get 9. All four on? F — fifteen, the biggest number four bits can hold.