CD BackUp RAM Cart

CD BackUp RAM US box.

The CD BackUp RAM Cart is a memory card designed for the Mega CD that plugs into the Mega Drive cartridge port. 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. The unit contains 2045 blocks (1 Mbit) of memory for game saves. 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

Manuals

• Backup RAM JP Manual ^(info) ()

Physical Scans

Mega CD, US
Cover

Mega CD, JP
<div style="margin:auto; max-width:px"> 320x120px320x120px320x120px Cover