Lunar Porter flies on a controller

A held thruster burns every tick it is held for, which is the whole reason
the pad exists: the console can only say a key went down, so a thruster
driven by it could be pumped and never leaned on.

The burn happens on the same tick gravity does, and for the same reason -
a sixteenth of a pixel is the smallest step this arithmetic takes, and
applied sixty times a second it is an enormous acceleration. On the tick,
thrust and gravity are two numbers whose RATIO is the whole feel of the
thing. Position still moves every frame; only the acceleration is stepped,
and nothing can see that.

Two against gravity's one, so climbing and falling are the same speed.
Three was the first try and it left the moon after about a second of
holding.

If there is a pad the console's arrows are ignored, because under a window
the same keypress reaches both - the pad as a level, the console as a byte
- and a thruster that fired twice for one press would be a mystery to
anybody tuning it. q still quits, since a pad has no letter for it. With
no pad the arrows still burn once a press, which is the most that can be
done down a wire.

And break.sh now rebuilds the disk images as well as the binaries. Half
the things worth breaking here are SplitBit assembly rather than C, and
those live on the fixture disks - so an edit to a .asm file changed
nothing the suite could see, and the tool reported that nothing caught the
break. That is the exact lie it was written to prevent, turning up in a
new place. With the disks rebuilt it catches this one: the lander falls
between the two captures instead of climbing.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW

Programs/CosmOS/README.md

@@ -726,7 +726,7 @@ from every assembly file in it. Several are old programs written for the bare ma
 | Break | Stops itself twice with SWI osBreak, so that the registers can be seen changing between one stop and the next. |
 | Grid | The first program to use the screen as a screen. Redefines a tile above the font, fills all 128 map rows, and scrolls it diagonally a pixel at a time. |
 | Sprite | Moves a ball across the shell's own text, writing not one byte of the map to do it. It leaves the sprite in the table on the way out, because clearing them is the system's job - see below. |
-| Lander | Lunar Porter, rung one: a lander over a moon that wraps. The map's column origin is a ring in hardware, so 128 cells of it is 1024 pixels of surface with no edge and no seam. Position and velocity are sixteen bit in sixteenths of a pixel, which is what makes going all the way round an AND rather than a comparison. |
+| Lander | Lunar Porter, rung one: a lander over a moon that wraps. Flown with a controller if there is one - a held thruster burns every tick it is held for - and with the arrow keys if there is not, where one press is one burn and that is the most the console can say. |
 | Depth | Four pillars at four distances and a ball walking past them, behind the near ones and in front of the far ones. The ball is sprite nought and every pillar is numbered after it, so table order puts it in front of all four - what actually decides is the depth buffer, asked a column at a time. |
 | Flip | Draws a whole screen into the bank that is not being shown, waits, and then shows it in one byte out of one port. It writes nothing else at all - not a tile, not a colour - so it does not ask for the screen to be saved, and the line it printed is still there when it comes back. It deliberately does not put the displayed screen back either, because that is the system's to restore: a program that faulted while flipped could not have. |
 | Edit | A line editor. |