The RL and RL/HD featured a surface-mounted 8086 processor, 512 KB of RAM (expandable to 768 KB to provide 128 KB for video and 640 KB conventional memory), a DB-25 unidirectional parallel port instead of the edge-connector ports, and the SL's enhanced graphics and sound. A single half-size 8-bit expansion slot was available. The RL/HD had a battery-backed real-time clock chip to store date and time information, which the RL lacked. These models also had MS-DOS and a portion of DeskMate in ROM, and could therefore boot much faster than many other computers on the market. The RL/HD came with a 20MB drive preinstalled.