amiga-bootcamp/01_hardware/README.md
2026-04-26 14:46:18 -04:00

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Hardware — Chipset Generation Overview

Generation Comparison

Feature OCS ECS AGA
Agnus 8361/8367 8372A (Super Agnus) Alice (8374)
Denise 8362 8373 (ECS Denise) Lisa
Paula 8364 8364 (unchanged) 8364 (unchanged)
Max Chip RAM 512 KB1 MB 12 MB 2 MB
Colors (max normal) 32 32 256
HAM 12-bit HAM (6bpp) 12-bit HAM 24-bit HAM8 (8bpp)
Sprites 8 × 16px 8 × 16px 8 × 64px, 256 colors
Blitter bus 16-bit 16-bit 64-bit (FMODE)
Display modes NTSC/PAL +Productivity, VGA +Doublescan, 31kHz
Machines A500/A1000/A2000/CDTV A600/A3000/A500+ A1200/A4000/A4000T/CD32

Custom Register Address Space

All chipset generations share the base address $00DFF000 for custom registers. Registers are memory-mapped, mostly 16-bit wide.

$DFF000  BLTDDAT   Blitter destination early read
$DFF002  DMACONR   DMA control (read)
$DFF004  VPOSR     Vertical position (read, high)
...
$DFF180  COLOR00   Color register 0
...
$DFF1FE  (last OCS/ECS register)
$DFF1FC  BEAMCON0  (ECS+) beam control
$DFF1FC+ (AGA extensions)

See custom_registers_full.md for the complete table across all chipsets.


Navigation

Subfolder Content
common/ M68k CPU, address space layout, memory types (Chip/Fast/Slow), CIA chips, Zorro bus, Gayle IDE/PCMCIA
ocs_a500/ OCS chipset — A500, A1000 (WCS), A2000 (Zorro II), CDTV (CD-ROM, NVRAM, IR)
ecs_a600_a3000/ ECS chipset — A600, A3000 (Gary system controller), A500+
aga_a1200_a4000/ AGA chipset — A1200, A4000, A4000T (SCSI), CD32 (Akiko C2P, CD-ROM, NVRAM)

References