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.

01_hardware/ecs_a600_a3000/gary_gayle.md

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+[← Home](../../README.md) · [Hardware](../README.md) · [ECS](README.md)
+
+# Gary & Gayle — System Controller Chips
+
+## Gary (A3000)
+
+**Gary** is the custom system controller chip in the A3000, combining functions that are discrete ICs on the A2000:
+
+- **Bus controller**: Manages the interaction between 68030/68882, chip bus, and Zorro III
+- **Auto-config controller**: Runs the Zorro expansion enumeration
+- **DMA arbitration**: Between 68030, custom chips, and Zorro III DMA
+- **SCSI interface glue**: Works with the A3000's built-in WD33C93 SCSI controller
+- **ROM decode**: Maps Kickstart ROM into the address space
+
+Gary is not directly programmable by user software; its configuration is set by hardware strapping and the ROM initialisation sequence.
+
+## Gayle (A600 / A1200)
+
+**Gayle** is the custom chip providing **IDE** and **PCMCIA** interface on the A600 and A1200. The A600 and A1200 use different Gayle revisions with different PCMCIA pinouts.
+
+### Gayle Identification
+
+```
+A600 Gayle revision ID: read from $DA8000
+A1200 Gayle revision ID: read from $DA8000
+```
+
+```asm
+move.b  $DA8000, d0    ; Read Gayle ID byte
+```
+
+| Byte | Machine |
+|---|---|
+| $D0 | A600 Gayle |
+| $D1 | A1200 Gayle (revision 1) |
+
+### Gayle Register Map (A600/A1200)
+
+| Address | Register | Description |
+|---|---|---|
+| $DA8000 | GAYLE_ID | Chip ID (read shifts bits) |
+| $DA9000 | GAYLE_INT_STATUS | Interrupt status |
+| $DA9004 | GAYLE_INT_ENABLE | Interrupt enable |
+| $DA9008 | GAYLE_CONTROL | Control register |
+
+### IDE Interface
+
+The IDE interface via Gayle is at `$DA0000` (A1200) or `$DA0000` (A600):
+
+| Offset | Register | Description |
+|---|---|---|
+| $DA0000 | DATA | IDE data register (16-bit) |
+| $DA0004 | ERROR/FEATURE | Error (read) / Feature (write) |
+| $DA0008 | SECTOR_COUNT | Sector count |
+| $DA000C | SECTOR_NUMBER | Sector number (LBA 7:0) |
+| $DA0010 | CYLINDER_LOW | Cylinder low (LBA 15:8) |
+| $DA0014 | CYLINDER_HIGH | Cylinder high (LBA 23:16) |
+| $DA0018 | DRIVE_HEAD | Drive/Head/LBA (LBA 27:24) |
+| $DA001C | STATUS/COMMAND | Status (read) / Command (write) |
+| $DA101C | ALT_STATUS | Alternate status (no interrupt clear) |
+| $DA101C | DEVICE_CONTROL | Device control (write) |
+
+> [!NOTE]
+> On the A1200, IDE registers are byte-wide on odd addresses in a 16-bit window. The data register is 16-bit. This differs from standard PC IDE — byte lanes are swapped relative to x86 convention.
+
+### PCMCIA Interface (A600/A1200)
+
+The A600 and A1200 support a Type II PCMCIA (PC Card) slot:
+
+| Address Range | Type | Description |
+|---|---|---|
+| $600000–$9FFFFF | Attribute memory | Card configuration (CIS access) |
+| $A00000–$A3FFFF | Common memory | Modem/network card data |
+| $A40000–$A7FFFF | Common memory (cont.) | |
+| $600000 (Gayle) | Gayle attribute | Gayle own config space |
+
+PCMCIA interrupt routing: Card interrupt → Gayle → CIA-A (`/FLG` pin) → CPU IPL 6.
+
+### Gayle Interrupt Bits
+
+```c
+/* DA9000 GAYLE_INT_STATUS */
+#define GAYLE_IRQ_IDE    (1<<6)  /* IDE drive interrupt */
+#define GAYLE_IRQ_CARD   (1<<5)  /* PCMCIA card interrupt */
+#define GAYLE_IRQ_BVD1   (1<<4)  /* PCMCIA battery voltage 1 */
+#define GAYLE_IRQ_BVD2   (1<<3)  /* PCMCIA battery voltage 2 */
+#define GAYLE_IRQ_WP     (1<<2)  /* PCMCIA write protect */
+#define GAYLE_IRQ_CD     (1<<1)  /* PCMCIA card detect */
+```
+
+### Gayle Power Control
+
+Gayle controls PCMCIA card power (5V / 3.3V on A1200 rev 1D+):
+```c
+/* GAYLE_CONTROL bits */
+#define GAYLE_POW        (1<<7)  /* PCMCIA power on */
+#define GAYLE_WS         (1<<6)  /* wait states for PCMCIA */
+```
+
+## AmigaOS IDE Access
+
+AmigaOS accesses the Gayle IDE through the `scsi.device` or dedicated `ata.device` driver provided with OS 3.1+. Direct IDE programming is done in the filesystem handler (`trackdisk.device` replacement).
+
+The standard path:
+```
+Application → dos.library → File System Handler → scsi.device → Gayle IDE
+```
+
+## References
+
+- Commodore A600 Technical Reference Manual — Gayle chapter
+- Commodore A1200 Technical Reference Manual — Gayle chapter
+- ADCD 2.1 — `Devices_Manual_guide/` scsi.device
+- NDK39: `hardware/gayle.h` (if present), community-documented Gayle registers