AnachronautandClaude Opus 5
d6c81fa32c
A lander over a moon that wraps. Landing, crashing, fuel, cargo and bases are not here - this rung exists to answer whether it FEELS right, because everything after it is bookkeeping and none of it is worth building on a lander that is no fun to fly. The moon comes for free. The map's column origin is a ring in hardware, so 128 cells is 1024 pixels of surface with no edge and no seam to cross. Position and velocity are sixteen bit in SIXTEENTHS OF A PIXEL, and the unit is the design: gravity is a small number added to a velocity and a velocity is a number added to a position, with no multiply or divide anywhere. 1024 pixels is 16,384 sixteenths, which is 2^14 - so going all the way round is an AND with 0x3FFF rather than a comparison, and it is never wrong at the seam. The lander never moves sideways. The world scrolls under it and it sits at the middle of the screen, which is a byte a frame instead of two and is also what makes the wrap invisible: there is no moment where it jumps. One key is one burn. The console says which key went down and there is no such thing as a key coming up, so a thruster cannot be held - a press adds to the velocity once. That is a property of the machine rather than a choice this program made, and it reads as pumping the engine. Four bugs found by running it, all worth keeping written down: B CANNOT BE A LOOP COUNTER here. Every comparison is an INIB, so the count was overwritten by whichever bound was last tested and the loop reset itself for ever. Counters that outlive arithmetic live in memory. A subroutine answers in Q, and the AND after it read A. The moon came out flat because it was testing the height against 1 instead of the random number. Row minus height, not height minus row: they are equal at the surface, equal does not borrow, and the surface row has to be ground. And the shift register has A as its HIGH half. Written the other way, the view scrolled by 256 cells for every one it should have. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
56 lines
1.4 KiB
Plaintext
56 lines
1.4 KiB
Plaintext
CosmOS
|
|
> Crash opcode
|
|
that byte is not an instruction, at 5081
|
|
A 00 B 0F Q 00
|
|
the program was stopped
|
|
> Crash service
|
|
nothing is installed at service 28, at 5084
|
|
A 00 B 0F Q 00
|
|
the program was stopped
|
|
> Crash bank
|
|
a bank that is not there, or an address past its end, at 509E
|
|
A 01 B 0F Q 00
|
|
the program was stopped
|
|
> Crash device
|
|
nothing is installed for the device on port 00, at 50A5
|
|
A 02 B 0F Q 00
|
|
the program was stopped
|
|
> Crash sideways
|
|
Crash opcode | service | bank | device | blind
|
|
finished
|
|
> dir
|
|
greet.sbx 211
|
|
hello.sbx 53
|
|
Life.sbx 1396
|
|
Snake.sbx 2164
|
|
Keys.sbx 664
|
|
Say.sbx 156
|
|
Break.sbx 149
|
|
Grid.sbx 571
|
|
Press.sbx 872
|
|
Mode.sbx 48
|
|
Flip.sbx 173
|
|
Sprite.sbx 442
|
|
Depth.sbx 672
|
|
Lander.sbx 984
|
|
Crash.sbx 632
|
|
vars.script 50
|
|
blocks.script 343
|
|
loops.script 272
|
|
tune.sbx 306
|
|
notes.txt 21
|
|
Apps <dir>
|
|
hi.script 121
|
|
bad.script 45
|
|
plain.script 24
|
|
cross.script 280
|
|
nonl.script 38
|
|
outer.script 376
|
|
inner.script 44
|
|
loop.script 35
|
|
28 files, 1 directory
|
|
> exit
|
|
halted
|
|
Execution halted.
|
|
[exit 0]
|