# Slalom (U)

## 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: 10,537 / 32,768 bytes (32.2%).
`make` assembles and verifies byte-identical to `rom.nes`.

## ROM

| Property | Value |
|----------|-------|
| Format | iNES |
| Mapper | 0 (NROM) |
| PRG | 32 KB |
| CHR | 8 KB |
| Mirroring | Vertical |
| NMI vector | $8123 |
| RESET vector | $8050 |
| IRQ vector | $FEDF |

## Power-on flow

RESET enters at `$8050`:

    sei                            ; CPU:$8050 PRG:0050  78
    cld                            ; CPU:$8051 PRG:0051  D8
    lda #$18                       ; CPU:$8052 PRG:0052  A9 18
    sta PPUCTRL                    ; CPU:$8054 PRG:0054  8D 00 20
    lda PPUSTATUS                  ; CPU:$8057 PRG:0057  AD 02 20
    bpl Reset_OnNonnegative        ; CPU:$805A PRG:005A  10 FB
    lda PPUSTATUS                  ; CPU:$805C PRG:005C  AD 02 20
    bpl Reset_OnNonnegative2       ; CPU:$805F PRG:005F  10 FB
    jsr Sub_B476                   ; CPU:$8061 PRG:0061  20 76 B4
    jsr Sub_8A6D                   ; CPU:$8064 PRG:0064  20 6D 8A
    lda #$FF                       ; CPU:$8067 PRG:0067  A9 FF
    sta $0731                      ; CPU:$8069 PRG:0069  8D 31 07

NMI handler at `$8123`:

    lda PPUSTATUS                  ; CPU:$8123 PRG:0123  AD 02 20
    lda #$00                       ; CPU:$8126 PRG:0126  A9 00
    sta OAMADDR                    ; CPU:$8128 PRG:0128  8D 03 20
    lda #$04                       ; CPU:$812B PRG:012B  A9 04
    sta OAMDMA                     ; CPU:$812D PRG:012D  8D 14 40
    jsr Sub_B438                   ; CPU:$8130 PRG:0130  20 38 B4
    ldx Zp02                       ; CPU:$8133 PRG:0133  A6 02
    lda $8142,x                    ; CPU:$8135 PRG:0135  BD 42 81

## Data-table inventory (Pass 3)

- `$8000-$804F` (80 bytes) - `CopyrightText`
- `$8142-$8165` (36 bytes) - `GameStateHandlerPointerTable`
- `$8287-$829A` (20 bytes) - `ObjectHandlerPointerTable`
- `$8347-$8372` (44 bytes) - `ObjectActionPointerTable`
- `$84C6-$84EB` (38 bytes) - `SkiRecordNameTable`
- `$85C5-$87F7` (563 bytes) - `PlayerNameText`
- `$8828-$8876` (79 bytes) - `WorldRecordText`
- `$8AD8-$8B25` (78 bytes) - `CourseNameTable`
- `$8B59-$8B7B` (35 bytes) - `CourseRecordTable`
- `$8CA1-$8CA6` (6 bytes) - `CharacterCharsetTable`
- `$8CE4-$8CF7` (20 bytes) - `GameOverText`
- `$8FB3-$9032` (128 bytes) - `SkierXPositionTable`
- `$9067-$9086` (32 bytes) - `SkierMovementTable`
- `$9125-$9130` (12 bytes) - `KeyboardInputMap`
- `$9205-$925C` (88 bytes) - `SlalomPathTable`
- `$9648-$966F` (40 bytes) - `SkierSpeedTable`

## Build

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