Expansion hardware

Some consoles were never one box. A Mega Drive grew a CD drive underneath it and a 32X out of its cartridge slot; a Nintendo 64 got a disk drive bolted to its floor; a Super Famicom took a Super Game Boy, a Sufami Turbo or the BS-X cartridge in the same slot an ordinary game went into.

Since v0.5.0 those are real objects in the room. You spawn the expansion, you spawn the console, and you stack them — the same way you would on a shelf.

Assembling a stack

It is one gesture

Spawn the expansion unit, then pick the console up and set it on top of the unit (or push the unit into the console’s cartridge slot, depending on which one it is). The two snap together into one machine.

Which way round depends on the hardware, and it follows the real thing:

Unit	Host	How it goes together
Sega CD	Mega Drive	The console stands on the drive
CD-ROM²	PC Engine	The console docks onto the interface unit
Nintendo 64DD	Nintendo 64	The console stands on the drive
Famicom Disk System	Famicom / NES	The console stands on the drive
Satellaview	Super Famicom	The base station sits under the console
32X	Mega Drive	Into the cartridge slot, with its own slot on top
Jaguar CD	Atari Jaguar	Into the cartridge slot, hanging over the back
Super Game Boy / SGB2	Super Famicom	Into the cartridge slot, Game Boy cart on top
Sufami Turbo	Super Famicom	Into the cartridge slot — and it takes two carts
BS-X	Super Famicom	Into the cartridge slot, 8M Memory Pack on top

A unit with a bay of its own takes its own media: a disc goes into the Sega CD’s tray, a disk into the 64DD, a Game Boy cartridge into the roof of a Super Game Boy. Where the real hardware had no mouth — the Satellaview base station is a tuner and a modem — the media goes into the console’s slot instead, exactly as it did in 1995.

The Sufami Turbo is the one with two wells, and that is not decoration: nine of its thirteen games link the cartridge in the second slot into the game in the first. It has a page of its own.

The core switches itself

An expansion often needs a different emulator from the console’s own default. A Mega Drive on its own is fine on one core; a Mega Drive with a 32X on it is a different machine and wants another.

You do not have to know which. When you build a stack, RetroXR resolves the combination and switches to the core that supports it — downloading it first if you do not have it yet. Take the stack apart and the console goes back to its usual core.

See about cores if you want to know which core is running.

Units that need a BIOS

Four of these are not consoles at all — they are cartridges carrying a program, and that program is firmware you supply. Until the file is installed, the unit is not offered in the spawn menu at all, because without it the unit would be a prop.

Unit	File	Goes in
Super Game Boy	SGB1.sfc	libretro/system/bsnes/
Super Game Boy 2	SGB2.sfc	libretro/system/bsnes/
Sufami Turbo	STBIOS.bin	libretro/system/snes9x/
BS-X	BS-X.bin	libretro/system/snes9x/

The BIOS / Extras view in the CORES tab shows which of these you have and verifies them — see BIOS and firmware for where those folders live on each platform.

SGB1 and SGB2 are told apart by the dump, not the filename

The two Super Game Boys are genuinely different machines — the original runs the handheld about 2.4% fast off the SNES clock, the 1998 revision carries its own crystal. Which one you get is decided by the header inside the ROM, so an SGB1 dump installed under the name SGB2.sfc quietly gives you two SGB1s. The BIOS view’s checksum verdict is where that shows up.

Saves

The battery is wherever the real hardware put it. A Super Game Boy has none — the save belongs to the Game Boy cartridge seated in it. A Sufami Turbo has none either, and both of its cartridges keep their own save. The BS-X unit does have one, holding the town and your name.

Satellaview+

The Satellaview’s broadcasts stopped in 2000, so what survives are dumps. Satellaview+ is a community client that streams a scheduled broadcast again, and v0.5.0 can receive it:

• Point the sat folder at the roms/satellaview folder that the Satellaview+ client writes into.
• Spawn 8M Memory Packs to save the transmissions you catch.

The Satellaview page covers the whole stack — the base station, the BS-X cartridge, the packs and the live broadcast.

PCVR only, for now

This needs the Satellaview+ client running alongside RetroXR, and there is no in-app client on Quest yet. On a standalone headset the Satellaview is still there — you just play the dumps you already have rather than a live broadcast.