docs(amiga): complete AmigaOS 3.1/3.2 developer reference — 172 files across 17 sections

Comprehensive technical documentation covering:
- Hardware: OCS/ECS/AGA custom chip registers, Copper & Blitter deep dives
- Boot sequence: cold boot through startup-sequence
- Binary format: HUNK executable spec, relocation, debug info
- Linking & ABI: .fd files, LVO tables, register calling conventions
- Exec kernel: tasks, interrupts, memory, signals, semaphores
- AmigaDOS: file I/O, FFS/OFS layout, CLI/Shell scripting
- Graphics: planar bitmaps, Copper programming, HAM/EHB modes
- Intuition: screens, windows, IDCMP, BOOPSI
- Devices: trackdisk, SCSI, serial, timer, audio, keyboard
- Libraries: utility, expansion, IFFParse, locale, ARexx
- Networking: bsdsocket API, SANA-II, TCP/IP stack comparison
- Toolchain: GCC, vasm/vlink, SAS/C, NDK, debugging
- Reverse engineering: IDA/Ghidra setup, compiler fingerprints, case studies
- CPU & MMU: 68040/060 emulation libs, PMMU, cache management
- Driver development: SANA-II, Picasso96/RTG, AHI audio

All files include breadcrumb navigation. No local paths or proprietary content.

12_networking/sana2.md

@@ -0,0 +1,78 @@
+[← Home](../README.md) · [Networking](README.md)
+
+# SANA-II — Standard Amiga Network Architecture
+
+## Overview
+
+SANA-II is the standard device driver interface for network hardware on AmigaOS. It defines a uniform API that TCP/IP stacks use to communicate with any network card (Ethernet, WiFi, PPP, etc.).
+
+---
+
+## Architecture
+
+```
+Application
+    ↓
+bsdsocket.library (TCP/IP stack)
+    ↓
+SANA-II device driver (e.g., prism2.device, a2065.device)
+    ↓
+Network hardware
+```
+
+---
+
+## Opening a SANA-II Device
+
+```c
+struct IOSana2Req *s2req = (struct IOSana2Req *)
+    CreateIORequest(port, sizeof(struct IOSana2Req));
+
+/* Provide buffer management hooks: */
+static struct TagItem s2tags[] = {
+    { S2_CopyToBuff,   (ULONG)CopyToBuff },
+    { S2_CopyFromBuff, (ULONG)CopyFromBuff },
+    { TAG_DONE, 0 }
+};
+s2req->ios2_BufferManagement = s2tags;
+
+OpenDevice("a2065.device", 0, (struct IORequest *)s2req, 0);
+```
+
+---
+
+## Commands
+
+| Code | Constant | Description |
+|---|---|---|
+| 2 | `CMD_READ` | Read a packet |
+| 3 | `CMD_WRITE` | Send a packet |
+| 9 | `S2_DEVICEQUERY` | Query hardware capabilities |
+| 10 | `S2_GETSTATIONADDRESS` | Get MAC address |
+| 11 | `S2_CONFIGINTERFACE` | Configure interface (set MAC) |
+| 14 | `S2_ONLINE` | Bring interface online |
+| 15 | `S2_OFFLINE` | Take interface offline |
+| 21 | `S2_GETGLOBALSTATS` | Get packet statistics |
+| 16 | `S2_ADDMULTICASTADDRESS` | Add multicast address |
+| 17 | `S2_DELMULTICASTADDRESS` | Remove multicast address |
+
+---
+
+## Packet Reading
+
+```c
+s2req->ios2_Req.io_Command = CMD_READ;
+s2req->ios2_WireError = 0;
+s2req->ios2_PacketType = 0x0800;  /* IPv4 */
+SendIO((struct IORequest *)s2req);
+/* wait for packet... */
+WaitIO((struct IORequest *)s2req);
+/* s2req->ios2_Data* contains the received packet */
+```
+
+---
+
+## References
+
+- SANA-II Network Device Driver Specification (Commodore)
+- NDK39: `devices/sana2.h`