Optical drive replacements

An optical drive replacement is a device that replaces the Dreamcast's GD-ROM drive with an alternative storage method, typically SD cards or USB storage. These devices typically use an FPGA to simulate the GD-ROM drive hardware. Because these are devices that simulate the system's original GD-ROM, the compatibility is virtually perfect with a few exceptions. Similarly, one could attempt the IDE hard drive modification to accomplish a similar goal, however as this does not simulate the system's hardware, software hacks must be applied by a loader program, resulting in some potential compatibility issues.

GD-ROM Optical Drive Features Comparison
Device:	GDEMU	USB-GDROM	MODE	iceGDROM
price and availability	€130 euros, periodic sales done on creator's website, price includes shipping from Poland $40-$80 USD unofficial China-based clones widely available worldwide	$180 USD to purchase as a Paypal gift $220 USD to purchase with Paypal protection additional $15 USD for shipping from Russia to worldwide sales through creator's website	€182, unreleased, ETA late-June or early-July, preorders open	DIY project
console revisions supported (none support va2 models)	va1 only (works in va0, but incorrect signal voltages may cause damage)	va0 and va1	va0 and va1	va1 only
media type	SD cards	USB 2.0 storage compatible with SATA to USB 2.0 bridges	SD, USB 2.0, SATA SATA through built-in USB 2.0 bridge	SD cards
media capacity	officially, up to 32GB large cards like 400GB and 512GB tested and widely used	up to 2TB	limited by storage device size	???
menu type	officially, no menu, controlled by hardware GDMenu graphical menu is current de facto default menu	text-based menu	List view and advanced covert art views	no menu, controlled by hardware
media format	FAT32 with images specifically named and in numbered folders community tools such as GDEmu SD card creator exist to assist in creating cards	FAT32, drag and drop	exFAT	FAT32, requires conversion to custom image format, files must be specifically numbered
image format	TOSEC GDI+BIN, GDI+ISO, CDI, CCD+IMG+SUB, MDS+MDF, ISO for homebrew disc-swapping (e.g. for emulator ROM discs)	TOSEC GDI+BIN, GDI+ISO, CDI	TOSEC GDI+BIN, GDI+ISO, CDI, CCD+IMG+SUB, MDS+MDF, Redump CUE+BIN/ISO
disc swapping	Yes, swap to next disc by pressing physical button Combined with DCDigital mod, allows swap to next disc in DCDigital menu	Yes, swap to any disc support in menu Combined with DCDigital mod, allows swap to next disc in DCDigital menu	Yes	Yes, swap to next disc by ejecting and re-inserting SD card
in-game reset	Yes, reboot console to menu with X+Y+B+A+Start	No, have to power cycle console with power button	???	???
custom loader/bleemshell support	allows custom coded menus with direct control of console, can control of disc-swapping done through hidden API Community menus exist including GDMenu, bleemshell, OpenMenu, etc.	none	none	none
bleemcast! GT2/TK3/MGS version support	no (support requires either firmware update to enhance CCD image support, or community effort to further crack protection)	no (support requires either firmware update to enhance CCD image support, or community effort to further crack protection)	???	no (support requires either firmware improvement for image support, or community effort to further crack protection)
known bugs	Item duplication bug on Resident Evil Code Veronica (critical bug) Freezing during Skies of Arcadia intro video (non-critical) D2 disc swapping bug	???	???	???
additional notes	Genuine devices are firmware-updatable, but clone devices are bricked if user attempts a firmware update All clones contain latest firmware	Previous versions of firmware included a hidden undisclosed self-bricking timebomb unless user periodically updated firmware in order to give creator control over devices, however the latest version firmware is supposedly free of this since the timebomb was publicized	also supports the Sega Saturn console	completely DIY open source project