21751c0025
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.
4.1 KiB
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
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
/* 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+):
/* 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