# 1942 (JU)

## Status

**Pass 3 complete; promoted.** `prg.s` is a traced disassembly with all
address-derived labels replaced, all `jsr`/`jmp` operands symbolic, hardware
registers named via `symbols.inc`, and `apply_symbols.py` reporting 0 residue.
Code coverage: 17,065 / 32,768 bytes (52.1%).
`make` assembles and verifies byte-identical to `rom.nes`.

## ROM

| Property | Value |
|----------|-------|
| Format | iNES |
| Mapper | 0 (NROM) |
| PRG | 32 KB |
| CHR | 8 KB |
| Mirroring | Horizontal |
| NMI vector | $C030 |
| RESET vector | $BF90 |
| IRQ vector | $BF90 |

## Power-on flow

RESET enters at `$BF90`:

    sei                            ; CPU:$BF90 PRG:3F90  78
    cld                            ; CPU:$BF91 PRG:3F91  D8
    ldx #$F3                       ; CPU:$BF92 PRG:3F92  A2 F3
    txs                            ; CPU:$BF94 PRG:3F94  9A
    lda #$10                       ; CPU:$BF95 PRG:3F95  A9 10
    sta PPUCTRL                    ; CPU:$BF97 PRG:3F97  8D 00 20
    lda PPUSTATUS                  ; CPU:$BF9A PRG:3F9A  AD 02 20
    bpl Reset_OnNonnegative        ; CPU:$BF9D PRG:3F9D  10 FB
    lda $07BD                      ; CPU:$BF9F PRG:3F9F  AD BD 07
    cmp #$55                       ; CPU:$BFA2 PRG:3FA2  C9 55
    bne Reset_Loop                 ; CPU:$BFA4 PRG:3FA4  D0 07
    lda $07BE                      ; CPU:$BFA6 PRG:3FA6  AD BE 07

NMI handler at `$C030`:

    sta Zp63                       ; CPU:$C030 PRG:4030  85 63
    stx Zp64                       ; CPU:$C032 PRG:4032  86 64
    sty Zp65                       ; CPU:$C034 PRG:4034  84 65
    lda PpuCtrlShadow                       ; CPU:$C036 PRG:4036  A5 8C
    and #$7F                       ; CPU:$C038 PRG:4038  29 7F
    sta PPUCTRL                    ; CPU:$C03A PRG:403A  8D 00 20
    sta PpuCtrlShadow                       ; CPU:$C03D PRG:403D  85 8C
    lda #$00                       ; CPU:$C03F PRG:403F  A9 00

## Data-table inventory (Pass 3)

- `$8494-$9FDA` (6983 bytes) - `LevelLayoutData`
- `$A08C-$A093` (8 bytes) - `PpuBitMaskTable`
- `$A2F2-$A311` (32 bytes) - `EnemyHandlerPointerTable`
- `$A3E2-$A73D` (860 bytes) - `LevelObjectSpawnTable`
- `$A770-$A815` (166 bytes) - `EnemySpritePatternTable`
- `$ABD0-$AC13` (68 bytes) - `EnemyHealthPointTable`
- `$AD99-$ADC8` (48 bytes) - `SpriteOamAttributeTable`
- `$B200-$B37A` (379 bytes) - `LevelTilemapData`
- `$B4DC-$B4DF` (4 bytes) - `PlayerScoreTable`
- `$B783-$B7C2` (64 bytes) - `EnemySpritePatternTable2`
- `$B9C5-$B9E4` (32 bytes) - `BoardBoundaryData`
- `$BB51-$BC85` (309 bytes) - `LevelGraphicData`
- `$BF0F-$BF57` (73 bytes) - `EnemyMovementDeltaTable`
- `$C366-$C3C9` (100 bytes) - `SpriteOamEntryTable`
- `$DF58-$DF7F` (40 bytes) - `EnemySpawnCoordinateTable`
- `$DFBE-$DFE5` (40 bytes) - `EnemySpawnCoordinateTable2`
- `$E19E-$E1DF` (66 bytes) - `EnemyMovementPatternTable`
- `$E24B-$E392` (328 bytes) - `EnemySpritePositionTable`
- `$E3A1-$EC0B` (2155 bytes) - `EnemyHandlerCodeTable`

## Build

```
Byte-identical ROM verified.
```