nescript/examples/sha256/background.ne

// sha256/background.ne — the static nametable.
//
// Painted once at reset-time (the first `background` declaration
// in the program is loaded before rendering is enabled). Contains
// the title banner, section labels, and the 5 × 8 keyboard grid.
// The Entering and Showing state handlers draw the dynamic input
// buffer, the cursor, and the 64-digit hash on top of this
// background via sprites.
//
// Legend characters are chosen to read cleanly when glanced over
// as ASCII art:
//   upper-case A-Z and 0-9      → their matching glyph tile
//   space ' '                   → blank tile (tile 44)
//   ':' ',' '-' '.'             → punctuation glyph tiles
//   '_'                         → space-key glyph on the keyboard
//   'p'                         → period-key glyph on the keyboard
//   '<' '>'                     → backspace / enter key glyphs
//
// `palette_map:` leaves every metatile on bg sub-palette 0; the
// keyboard keys render as lt_gray (palette index 2), which reads
// cleanly against the dk_blue universal background.

background Screen {
    legend {
        " ": 44   // blank (universal colour)
        "A": 1
        "B": 2
        "C": 3
        "D": 4
        "E": 5
        "F": 6
        "G": 7
        "H": 8
        "I": 9
        "J": 10
        "K": 11
        "L": 12
        "M": 13
        "N": 14
        "O": 15
        "P": 16
        "Q": 17
        "R": 18
        "S": 19
        "T": 20
        "U": 21
        "V": 22
        "W": 23
        "X": 24
        "Y": 25
        "Z": 26
        "0": 27
        "1": 28
        "2": 29
        "3": 30
        "4": 31
        "5": 32
        "6": 33
        "7": 34
        "8": 35
        "9": 36
        "_": 37   // space-key glyph (underscore bar)
        "p": 38   // period-key glyph
        ":": 39
        "-": 40
        "<": 41   // backspace
        ">": 42   // enter
    }

    map: [
        "                                ",   // row 0
        "         SHA-256 HASHER         ",   // row 1 — title
        "                                ",   // row 2
        "  INPUT:                        ",   // row 3 — input label
        "                                ",   // row 4 — input row A
        "                                ",   // row 5 — input row B
        "                                ",   // row 6
        "  TYPE A MESSAGE  PRESS >       ",   // row 7 — prompt
        "                                ",   // row 8
        "                                ",   // row 9
        "                                ",   // row 10
        "                                ",   // row 11
        "           A B C D E F G H      ",   // row 12 — kb row 0
        "           I J K L M N O P      ",   // row 13 — kb row 1
        "           Q R S T U V W X      ",   // row 14 — kb row 2
        "           Y Z 0 1 2 3 4 5      ",   // row 15 — kb row 3
        "           6 7 8 9 _ p < >      ",   // row 16 — kb row 4
        "                                ",   // row 17
        "                                ",   // row 18
        "                                ",   // row 19
        "  SHA-256:                      ",   // row 20 — hash label
        "                                ",   // row 21 — hash rows
        "                                ",   // row 22
        "                                ",   // row 23
        "                                ",   // row 24
        "                                ",   // row 25
        "                                ",   // row 26
        "                                ",   // row 27
        "                                ",   // row 28
        "                                "    // row 29
    ]
}
-												examples/sha256: interactive SHA-256 hasher with on-screen keyboard

An end-to-end FIPS 180-4 SHA-256 hasher running entirely on the NES.
The player types up to 16 ASCII characters on a 5x8 on-screen
keyboard, presses Enter, and the program computes and displays the
64-character hex digest.

Layout (`examples/sha256/*.ne`):
  constants.ne         layout + K[64] / H_INIT[8] tables
                       (declared as `var` with init_array because the
                       v0.1 compiler treats `const u8[N] = [...]` as
                       a no-op — noted in the file)
  assets.ne            44-tile Tileset (A..Z, 0..9, punctuation,
                       special keys, cursor) shared between BG and
                       sprite layers
  background.ne        static nametable (title, labels, keyboard
                       grid) painted at reset
  state.ne             globals
  sha_core.ne          32-bit byte primitives (copy, xor, and, add,
                       not, rotr, shr) in inline asm + sigma/Sigma
                       mixers + schedule/round steps + fold
  render.ne            OAM helpers for cursor, input buffer, and
                       64-nibble digest
  keyboard.ne          key dispatch table
  entering_state.ne    cursor navigation + typing + auto-demo
  computing_state.ne   phased driver (48 schedule steps + 64 rounds
                       + fold across ~30 frames at 4 iterations each)
  showing_state.ne     renders the 256-bit digest as 8 rows of 8
                       sprite glyphs

Implementation notes:
  - All 32-bit words live as 4 little-endian bytes in `wk[64]`,
    `w[256]`, `h_state[32]` so every primitive walks four bytes with
    `LDA {arr},X`/`STA {arr},X` chains and, for adds, a carry chain.
  - Every primitive reads its parameters straight out of the
    transport slots `$04`/`$05` rather than `{dst}`/`{src}`
    substitutions: the inline-asm resolver looks parameters up in
    the analyzer's allocation table but the codegen spills them to a
    different per-function RAM slot, so `{dst}` would resolve to a
    ZP slot nothing ever writes to. Bypassing the substitution
    entirely sidesteps the issue without a compiler change.
  - Rotate-right by any amount is a byte-rotate loop plus a bit-
    rotate loop so the 10 SHA amounts (2, 6, 7, 11, 13, 17, 18, 19,
    22, 25) all compile to a handful of chained `ROR`s.
  - The headless jsnes golden auto-types "NES" after 1 s of idle and
    captures its SHA-256 digest
    AE9145DB5CABC41FE34B54E34AF8881F462362EA20FD8F861B26532FFBB84E0D
    — byte-identical to `shasum` / `hashlib.sha256(b"NES")`.

Build: `cargo run --release -- build examples/sha256.ne`

https://claude.ai/code/session_01FRmSBruVWCufm3LsUVMs8v

											
										
										
											2026-04-16 14:02:58 +00:00
+								// sha256/background.ne — the static nametable.
 								//
 								// Painted once at reset-time (the first `background` declaration
 								// in the program is loaded before rendering is enabled). Contains
 								// the title banner, section labels, and the 5 × 8 keyboard grid.
 								// The Entering and Showing state handlers draw the dynamic input
 								// buffer, the cursor, and the 64-digit hash on top of this
 								// background via sprites.
 								//
 								// Legend characters are chosen to read cleanly when glanced over
 								// as ASCII art:
 								//   upper-case A-Z and 0-9      → their matching glyph tile
 								//   space ' '                   → blank tile (tile 44)
 								//   ':' ',' '-' '.'             → punctuation glyph tiles
 								//   '_'                         → space-key glyph on the keyboard
 								//   'p'                         → period-key glyph on the keyboard
 								//   '<' '>'                     → backspace / enter key glyphs
 								//
 								// `palette_map:` leaves every metatile on bg sub-palette 0; the
 								// keyboard keys render as lt_gray (palette index 2), which reads
 								// cleanly against the dk_blue universal background.
 								background Screen {
 								    legend {
 								        " ": 44   // blank (universal colour)
 								        "A": 1
 								        "B": 2
 								        "C": 3
 								        "D": 4
 								        "E": 5
 								        "F": 6
 								        "G": 7
 								        "H": 8
 								        "I": 9
 								        "J": 10
 								        "K": 11
 								        "L": 12
 								        "M": 13
 								        "N": 14
 								        "O": 15
 								        "P": 16
 								        "Q": 17
 								        "R": 18
 								        "S": 19
 								        "T": 20
 								        "U": 21
 								        "V": 22
 								        "W": 23
 								        "X": 24
 								        "Y": 25
 								        "Z": 26
 								        "0": 27
 								        "1": 28
 								        "2": 29
 								        "3": 30
 								        "4": 31
 								        "5": 32
 								        "6": 33
 								        "7": 34
 								        "8": 35
 								        "9": 36
 								        "_": 37   // space-key glyph (underscore bar)
 								        "p": 38   // period-key glyph
 								        ":": 39
 								        "-": 40
 								        "<": 41   // backspace
 								        ">": 42   // enter
 								    }
 								    map: [
 								        "                                ",   // row 0
 								        "         SHA-256 HASHER         ",   // row 1 — title
 								        "                                ",   // row 2
 								        "  INPUT:                        ",   // row 3 — input label
 								        "                                ",   // row 4 — input row A
 								        "                                ",   // row 5 — input row B
 								        "                                ",   // row 6
 								        "  TYPE A MESSAGE  PRESS >       ",   // row 7 — prompt
 								        "                                ",   // row 8
 								        "                                ",   // row 9
 								        "                                ",   // row 10
 								        "                                ",   // row 11
 								        "           A B C D E F G H      ",   // row 12 — kb row 0
 								        "           I J K L M N O P      ",   // row 13 — kb row 1
 								        "           Q R S T U V W X      ",   // row 14 — kb row 2
 								        "           Y Z 0 1 2 3 4 5      ",   // row 15 — kb row 3
 								        "           6 7 8 9 _ p < >      ",   // row 16 — kb row 4
 								        "                                ",   // row 17
 								        "                                ",   // row 18
 								        "                                ",   // row 19
 								        "  SHA-256:                      ",   // row 20 — hash label
 								        "                                ",   // row 21 — hash rows
 								        "                                ",   // row 22
 								        "                                ",   // row 23
 								        "                                ",   // row 24
 								        "                                ",   // row 25
 								        "                                ",   // row 26
 								        "                                ",   // row 27
 								        "                                ",   // row 28
 								        "                                "    // row 29
 								    ]
 								}