CD32-native-cpuspeed
Build date: 2026-05-18  (BUILD_DATE=260518)
Minimig.rbf sha256-16: 4CF2B9C71F5CF977
MiSTer      sha256-16: 4A2EDF6B374C4030

The build date is also baked into the bitstream and visible in the OSD
"Info" / "About" screen as the "v260518" version line.

Inherits everything from CD32-native-cmdparity (2026-05-15).

Changes since 2026-05-15:
- New OSD entry: "CPU Speed: 14 MHz / Full" (replaces the old Turbo +
  experimental I-Cache entries). CFG byte bit 5 (offset 0x141E).
  - Full   = unchanged behavior, ~13.7 MIPS / 1.09x A1200 = far-too-fast
             (turbochip+turbokick shadow + no CPU throttle)
  - 14 MHz = clkena cooldown throttle gates TG68k pipeline to 1-in-10
             sysclks. ~1.38 MIPS / 1.09x A1200 = real-A1200-stock match,
             regardless of FastRAM or D-Cache setting. AIBB perf graphs
             align with stock 020 reference.
- turbochip/turbokick now stay ON in 14 MHz mode (was OFF in cmdparity).
  Chip RAM + Kickstart remain shadowed to fast SRAM; only the CPU
  pipeline is throttled. This isolates CPU-speed authenticity from
  memory-pacing concerns.
