A more upscale offering, the RSX offered a 25 MHz 80386SX processor, 1 MB RAM, two 16-bit ISA slots, AcuMos SVGA video, a bidirectional parallel port, and standard PS/2 keyboard and mouse ports. It was a full 386-class PC and could run Microsoft Windows 3.x. Two sockets for SIMM memory cards were provided. Only 1 MB or 4 MB SIMMs of the 9-chip type were supported, and if two were installed they had to be of like capacity. With two 4 MB SIMMs installed, the 1000 RSX could be expanded to 9 MB RAM (without using an ISA slot). The RSX/HD variant came with a 52 MB hard drive using an AT-compatible IDE interface; replacement hard drives up to 504 MB could be substituted. Because of the slimline case, only one hard drive could be installed alongside the 1.44 MB 3.5" floppy drive.