MSXnano v1.8 — ColecoVision/SG-1000 emulation + Metal Gear 2 fix

Highlights

• 🕹️ ColecoVision & Sega SG-1000 emulation — drop a .col / .sg ROM on the SD card and launch it straight from the boot menu (SN76489 sound chip; ColecoVision needs COLECO.ROM on the SD).
• 🐞 Metal Gear 2 — Solid Snake fixed — the gameplay-start graphics glitch (loading screen not clearing, mixing with the game) is resolved.

Fixes

• MG2 page-flip glitch. The boot menu highlights the selected entry using the VDP blink register (R#13); on the V9938/V9958 that value forces display page 0, so MG2's loading→stage page-flip was ignored and the loading screen stayed on screen. The launcher now resets R#13/R#12 (plus a VDP command STOP for the boot-splash residue) before the cartridge INIT — fixing MG2 and any page-flipping game launched from the menu. Launching from MSX-DOS/SofaRun was already clean because DOS leaves R#13 = 0.
• SG-1000 / ColecoVision joystick & keypad address fixes.

Flashing

• msxnano.fs → FPGA at 0x000000
• BIOS pack goauld_rom_int.bin → 0x200000
• BL616 FPGA Companion firmware as per the README (mind the keyboard caveat for new Tang Nano 20K 3921 boards).

Notes

• Console mode (ColecoVision / SG-1000) is newer than the mature MSX path; the ColecoVision numeric keypad mapping in particular may still receive tweaks.