CD BackUp RAM Cart

From Sega Retro

BackupRAM MCD US Cart.jpg
CD BackUp RAM Cart
Made for: Sega Mega-CD
Manufacturer: Sega
Type: Memory card
Release Date RRP Code
Sega Mega-CD
¥6,3006,300 G-2920
Sega Mega-CD

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CD BackUp RAM Cart or Backup RAM Cartridge (バックアップRAMカートリッジ) is a memory card designed for the Sega Mega-CD that plugs into the Sega Mega Drive cartridge port.


It is for use with Mega CD games which require the user to save, as unlike ROM cartridges, there is no way of saving data on the disc itself. The unit contains 2045 blocks (1 Mbit) of memory for game saves.

For the North American version, the cart resembles a regular Genesis cartridge, aside from a blue edging saying "Sega CD", as opposed to the usual red edging found on standard Genesis cartridges. Some RPGs - most notably Shining Force CD - used this for memory, as there was often not enough space for the save files in the internal backup RAM. In the case of Shining Force CD, this cartridge allows the player to unlock the last story segment of the game, inaccessible without the backup cart due to the Sega CD's internal memory limitations.

Maximum capacity

While the only officially-released RAM cartridge for the Sega CD has a capacity of 1 Mbit (128 KB; 2045 blocks), the system actually supports up to 4 Mbit (512 KB; 8189 blocks). The memory size is specified by a 3-bit value mapped to Main 68000 address $400001. This value indicates the memory size as a power of two, multiplied by the base memory size of 8 KB.

Memory Size
3-bit Value
@ $400001
Size (Kbit) Size (KB)
000 64 Kbit 8 KB
001 128 Kbit 16 KB
010 256 Kbit 32 KB
011 512 Kbit 64 KB
100 1024 Kbit 128 KB
101 2048 Kbit 256 KB
110 4096 Kbit 512 KB
111 not present



Localised names

Also known as
Language Localised Name English Translation
English (US) CD BackUp RAM Cart CD BackUp RAM Cart
Japanese バックアップRAMカートリッジ Backup RAM Cartridge

Magazine articles

Main article: CD BackUp RAM Cart/Magazine articles.

Physical scans

Mega-CD, JP
Backup MCD JP Cover.jpg
BackupRAM MCD JP Cart Back.jpgBackupRAM MCD JP Cart.jpg
Backupram mcd jp manual.pdf
BackupRAM MCD JP Cart Label.jpg
Mega-CD, US
Back Up Ram Cart MCD US Box Back.jpgBack Up Ram Cart MCD US Box Spine.jpgSegacd cdbackupramcart.jpg
BackupRAM MCD US Cart.jpg
Backupram mcd us manual.pdf

External links

  • Sega of Japan catalogue pages (Japanese): Mega-CD


Sega Mega-CD
Topics Technical specifications | History | Magazine articles | Promotional material
Hardware Mega CD (Asia | North America | Western Europe | Eastern Europe | South America | Australasia | Africa)
Sega Multi-Mega (Asia | North America | Europe | South America | Australasia)
Wondermega | LaserActive | CSD-G1M
Misc. hardware CD BackUp RAM Cart | Mega-CD Karaoke | Pro CDX
Development tools SNASM Mega-CD | PsyQ Mega-CD SDK | PSY-Q CD Emulation System (Mega-CD)
Unreleased hardware Game Genie