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.

13_toolchain/sasc.md

@@ -0,0 +1,63 @@
+[← Home](../README.md) · [Toolchain](README.md)
+
+# SAS/C 6.x — Compiler Reference
+
+## Overview
+
+SAS/C (originally Lattice C) was the dominant commercial C compiler for AmigaOS. Version 6.58 is the final release. It produces optimised 68k code with full AmigaOS integration, including pragma-based system calls and SAS-specific debug formats.
+
+---
+
+## Key Features
+
+| Feature | Description |
+|---|---|
+| Register args | Automatic register parameter passing |
+| Pragmas | `#pragma libcall` for direct library LVO calls |
+| Small data | A4-relative addressing for globals |
+| Profiling | Built-in `sprof` profiler |
+| Debug format | SAS stabs (`=APS` tag in HUNK_DEBUG) |
+| Optimizer | Global optimizer (`lc -O`) with peephole |
+
+---
+
+## Pragma Format
+
+```c
+/* dos_pragmas.h — generated from FD files: */
+#pragma libcall DOSBase Open 1e 2102
+/*                       ^^   ^^ ^^^^
+                         name LVO reg-encoding
+   reg-encoding: 2=D2, 1=D1, 0=result in D0, 2 args */
+
+#pragma libcall DOSBase Close 24 101
+#pragma libcall DOSBase Read 2a 32103
+```
+
+Register encoding: digits map to registers (1=D0, 2=D1, ... 9=A0, A=A1, etc.)
+
+---
+
+## Compilation
+
+```
+lc -v -O -b0 -j73 hello.c     ; compile
+blink hello.o TO hello LIB lib:sc.lib lib:amiga.lib  ; link
+```
+
+| Flag | Meaning |
+|---|---|
+| `-v` | Verbose |
+| `-O` | Optimise |
+| `-b0` | Small data model (A4-relative) |
+| `-b1` | Large data model |
+| `-j73` | Generate 68020/68881 code |
+| `-d0` | No debug info |
+| `-d2` | Full debug info |
+
+---
+
+## References
+
+- SAS/C 6.x User Manual
+- NDK39 pragma files: `NDK_3.9/Include/pragmas/`