The R-8 has one RAM memory card slot for saving user-created patterns and songs, and one slot for PCM ROM cards to augment the internal sound banks.
The R-8M is a rackmount version of the R-8, lacking the trigger pads and the sequencer capability, but with three front-facing ROM card slots. These sound libraries may be accessed simultaneously. This device was available from 1989 through 1994. The rack version has fewer individual outputs: 6 instead of 8.[2]
In 1992, Roland released a second version of the R-8 drum machine, the R-8 MKII. This version offers greatly expanded memory. User pattern memory was doubled from 100 to 200, arranged in two banks of 100, A and B. The ROM went from 67 to 199 samples.[3] It brought onboard content from the PCM cards SN-R8-01, SN-R8-02, SN-R8-09, SN-R8-10 and most of the 808 samples from SN-R8-04, while losing 22 of the MK1 samples. Another 16 samples from the MK1 returned in a slightly modified version with another name. A minor omission on the MKII is the absence of the Space Invaders boot screen. This device was discontinued in 1996.
Roland also released a trimmed-down version of the R8 in the form of the Roland R-5, which had fewer sounds and features than the R-8[4]
PCM sound cards
Known Roland ROM cards, each containing 26 samples:[5]
Roland SN-R8-01 - Contemporary Percussion
Roland SN-R8-02 - Jazz Brush
Roland SN-R8-03 - Sound Effects
Roland SN-R8-04 - Electronic (Contains 11 TR-808 samples)
Roland SN-R8-05 - Jazz
Roland SN-R8-06 - Ethnic Percussion
Roland SN-R8-07 - Mallet
Roland SN-R8-08 - Dry
Roland SN-R8-09 - Power Drums U.S.A.
Roland SN-R8-10 - Dance (Contains 6 TR-909 and 10 CR-78 samples)