Technology · Item
Serial screen
A thin screen that shows the characters a chip sends on a serial cable: text, gauges and pictures in a medieval code page of 256 characters.
In the game
How to get it
At the grid: 3 cells of glass, copper wire on each side of a gold ingot, planks on each side of a glowing backlight: 12 tiles. Click to place a 4 x 3 screen, or drag to size it (2 to 16 x 1 to 12 voxels); wire a chip's output to its Serial in.
What it is for
Show a factory's state, menus, bar graphs, games and pixel pictures; a satellite's weather station.
Why it exists
A chip with a screen becomes a computer: the most fun part of the OWL-8.
The same text the game shows in its progress tree and on the item's sheet (I).
How to get it
At the grid: 3 cells of glass (top row), copper wire on each side of a gold ingot, planks on each side of a glowing part (the backlight): 12 tiles, one per voxel of screen.
Placing it
Half a voxel thick, on a wall or standing. One click places a 4 x 3 screen; click and drag chooses from 2 x 1 to 16 x 12 voxels. Each voxel shows 3 x 2 characters.
How it works
- Inputs Serial in and Freeze. Each byte received is written at the bottom right and the text scrolls.
- Freeze at 128 or more holds the picture, so a whole image can be drawn then shown at once.
- A chip sends one byte per turn; screen_show (the SENDM instruction) sends a whole 12 x 6 image in about 3.6 s while the program goes on. Smaller screens refresh faster.
The code page
Every one of the 256 codes draws (but 0, 32 and 224, the blanks), hand-drawn in the interface's medieval style, 8 x 12 pixels:
| Codes | Characters |
|---|---|
| 1-31 | symbols and icons |
| 33-126 | medieval ASCII letters, digits and signs |
| 127 | € |
| 128-175 | accented Latin letters (French, Spanish, German, Portuguese), « » |
| 176-178, 240-243 | a nine-level grey ramp, dithered to tile across cells |
| 179-218 | box drawing |
| 219-223 | blocks (219 = a full cell) |
| 224-239 | quadrants (224 + mask) |
| 244-247 | diagonal halves |
| 248-255 | signs and a fleuron |
In C and assembly, text in quotes is turned into these codes ("Été ▒" sends what it shows); GRAY0..GRAY8, screen_gray(level) and screen_quad(mask) draw shades and quadrants.
On the progress path
EA4Advanced electronicsSide quest
- BeforeEA3 · OWL-8 microcontroller
- This stepEA4 · Serial screen
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