NGP.emu - RetroBIOS¶
Technical notes
Member of the EX Emulator series by Robert Broglia, which targets Android and Linux (README.md:1,3-4,12-13) and keeps iOS and Pandora build shortcuts in the tree (NGP.emu/ios.mk, NGP.emu/pandora.mk). Published as com.explusalpha.NgpEmu (NGP.emu/metadata/conf.mk:2,4,6,7) and reached by ES-DE through its NGP-EMU find rule, which only the Android rule set carries. Mednafen's Neo Geo Pocket module, itself descended from NeoPop, is vendored under NGP.emu/src/ngp (NGP.emu/metadata/conf.mk:8, NGP.emu/src/main/AppMeta.cc:27) on the 1.32 line (EmuFramework/include/shared/mednafen/mednafen-config.h:167) and driven by the app's own video, audio, input and save layers. Three files differ from the Mednafen 1.32.1 release, all of it frontend plumbing: the pixel format and sound rate hooks, the input latch and the flash file I/O move to the app (NGP.emu/src/main/Main.cc:84,102,118-131, NGP.emu/src/main/system.ccm:87,93). The TLCS-900h disassembler is left out of the build (NGP.emu/src/CMakeLists.txt:6-32). Content is read from .ngp, .ngc, .npc and .ngpc files (NGP.emu/metadata/conf.mk:5, NGP.emu/src/main/AppMeta.cc:31-34, NGP.emu/src/ngp/neopop.cpp:336-337); an archive is opened by the framework, which keeps the first entry passing that same filter (EmuFramework/src/EmuSystem.cc:392-412).
The content image is the only one the app loads. It is read into a 4 MiB buffer, hashed for the save file names and handed to the module, which refuses an image over 8 MiB (NGP.emu/src/main/Main.cc:80-85, EmuFramework/src/shared/mednafen-emuex/MDFNUtils.hh:133-146, NGP.emu/src/ngp/neopop.cpp:183-193). The BIOS is built in memory rather than read: bios_install fills a 64 KiB array with the 27 system call vectors, writes opcode 0x1F at each target, copies an 0x800 byte system font held in the binary to 0x8DCF and closes the image with a RETI and an infinite loop (NGP.emu/src/ngp/bios.cpp:29,50-180,182-239, NGP.emu/src/ngp/neopop.cpp:211). That opcode is bound to the HLE handler in the interpreter decode table, and the handler answers only from the 0xFF0000 region (NGP.emu/src/ngp/TLCS-900h/TLCS900h_interpret.cpp:921-926, NGP.emu/src/ngp/biosHLE.cpp:43-47). The same array is what the memory map returns for the BIOS region and where the font routine reads its glyphs (NGP.emu/src/ngp/mem.cpp:121, NGP.emu/src/ngp/biosHLE.cpp:221). The NGP Language menu item feeds the ngp.language setting, written to RAM at boot rather than selecting a file (NGP.emu/src/main/EmuMenuViews.cc:31-40, NGP.emu/src/main/options.cc:82-83, NGP.emu/src/ngp/mem.cpp:620, NGP.emu/src/ngp/neopop.cpp:286-299).
No firmware path exists by construction: the app answers Mednafen's file name request for save states, saves and save backups only, and any other kind ends in unreachable() (NGP.emu/src/main/options.cc:96-106). Cheat loading and IPS patching are compiled in from the shared Mednafen sources and called from nowhere (EmuFramework/src/shared/mednafen/mempatcher.cpp:251-254, EmuFramework/src/shared/mednafen/file.cpp:38-53). Per content the app writes and reads back a .ngf image holding the cartridge flash, plus save states and NgpEmu.config (NGP.emu/src/main/Main.cc:53-73,118-131, NGP.emu/src/main/system.ccm:76, NGP.emu/src/main/AppMeta.cc:28). ui.png, gpOverlay.png and the shader sources are drawn from the application bundle (EmuFramework/include/emuframework/AssetManager.hh:61-66, EmuFramework/src/AssetManager.cc:58-65, EmuFramework/src/VideoImageEffect.cc:163-173). The app declares no bundled content, the framework definition defaulting to an empty span (EmuFramework/src/AppMeta.cc:40, EmuFramework/include/emuframework/AppMeta.hh:66-68).
No BIOS or firmware files required. Generated on 2026-08-23T16:12:06Z