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+# Hardware
+
+Static facts about the Lofi-12 XT hardware (own teardown + photos in
+`photos/`). Behavioral/firmware side: `../FINDINGS.md`, `bootloader.md`.
+
+## Boards
+
+| PCB | Role |
+|---|---|
+| `405-VTOR-3852` | I/O board (jacks, MIDI, relays `HFD4/5`, USB-C area) |
+| `405-VTOR-3849B` | Main board (`28-AUG-2023` rev on unit): SD slot, MCU, power, FFC to UI |
+| `405-VTOR-3853` | Jack sub-board (`2/JUN/2022`) |
+| core module (unmarked) | Compute: SoC + DDR + 2× SPI flash, board-to-board `CN200A/CN201A/CN203A/CN203B` |
+
+## Chips (all confirmed visually)
+
+- **TI TMS320C6748** (`TMS320 C6748EZW T / 13CP99W`) — main SoC, ARM9 + C674x DSP.
+- **EtronTech EM68C16CWQG-25H** (`B07DY15MSYA0051`) — 1 Gbit DDR2.
+- **2× Macronix MX25L12833F** (`MXIC MX 25L12833F M2I-10G`), 16 MiB SPI NOR each,
+  silkscreen `IC300` (boot+app) / `IC301` (data). Factory stickers cover the
+  marking (`C047`/`C949`-style labels) — peel + photograph before any clip work.
+- **ARTERY AT32F421K8T** — USB/aux MCU, separate firmware (strings reference
+  `updateMCUSection`/`updateMCUBootSection`; protocol not reversed).
+
+## Memory map (DDR2, base `0xC0000000`, 128 MB)
+
+| Region | Use |
+|---|---|
+| `0xC2xxxxxx` | SD `.bin` application image (v1.5: code `C2B80C00`, strings `C2D84DE0`) |
+| `0xC7074630–C70B0598` | SPI AIS bootloader image, entry `C70A28A0` |
+| `0xC706F280` | Updater constant (file/scratch buffer area) |
+| `0xC27C6282` | Updater DDR scratch; value reused as checksum seed |
+
+## Rails / probing
+
+- Flash `VCC` measures 3.3 V in-circuit — never apply 5 V (see `RE-PROCESS.md` §1).
+- Jack board silkscreen: `A+7.5V / AGND / A-7.5V` analog rails, `DSU`/`AGNC`.
+- Main-board silkscreen tables name `UART1_RX1/TX1`, `SPI1_SCK/MOSI`, `SD_*`,
+  `USB_DP/DN`, key matrix (`KS1–KS6`, `EN_1A–5B`), `TP1–TP5` — candidates for
+  UART/JTAG mapping (continuity not yet traced; see `uart-zoom.jpg`).
+
+## Photos
+
+![Core module: TMS320C6748 + DDR2 + IC300/IC301](photos/core-module-top.jpg)
+*Core module — SoC, DDR2 and both SPI flashes (bottom edge).*
+
+![IC300 (left) + IC301 (right), stickers removed](photos/ic300-ic301-closeup.jpg)
+*Both are Macronix MX25L12833F, 16 MiB. Pin-1 dots face down-left; note the
+`IC300`/`IC301` silkscreen between the packages.*
+
+![UART area](photos/uart-zoom.jpg)
+*Close-up of the UART test-point area (unannotated).*