New Mappers:

Three previously-unsupported cartridge mappers now load and run under SGB emulation. All three reuse existing MbcState fields, so the GB savestate layout is unchanged.

• HuC1 (cart type $FD→ $FF) — Was a read-only stub, so ROM-bank-select writes were dropped and the game jumped into the wrong bank and locked up executing $FC filler.
  Reimplemented as MBC1-with-infrared (ROM/RAM banking + IR register). Fixes Chousoku Spinner, Pokémon Trading Card Game.
• HuC3 (cart type $FE) — Added the RTC command/response interface plus IR; boot gates on the RTC status command reading back ready. Fixes Robopon (Sun Version).
• Bandai TAMA5 (cart type $FD) — The ROM was rejected at load entirely. Implemented its unusual two-register port ($A001 selects, $A000 carries one nibble), a 32-byte battery-backed EEPROM, the $0A ready handshake, and the TAMA6 RTC. Fixes Game de Hakken!! Tamagotchi - Osutchi to Mesutchi.

Game Boy / Super Game Boy fixes:

• MBC5 keeps cart RAM readable when RAM-enable is off (2026-05-29). Some games run a trampoline out of SRAM; returning $FF while disabled hung them at boot. Fixes the Nettou King
  of Fighters '97 SGB boot hang.
• Optional frame-blend toggle — PR #87. Games that fake transparency by flickering two backgrounds (e.g. Chikyuu Kaihou Gun ZAS) can now blend each displayed frame 50/50 with the
  previous one at the shared end-of-frame hook. New "Blend Game Boy Frames" checkbox in Display Settings.
• Independent GB volume slider in SGB BIOS mode