The machine is based on a powerful (for the time) 16-bit single-chip K1801VM1 CPU, clocked generally at 3 MHz. It is almost perfectly compatible with Digital Equipment Corporation's LSI-11 line, though it lacks EIS and further instruction set extensions. The manufacturer also closely copied the PDP-11's internal architecture. Each model has one free card slot which is electrically, but not mechanically, compatible with Q-Bus. The first versions has 32 KiB onboard DRAM, half of which was used as video memory. That is extended to 128 KiB in later models, with video memory extended to two 16 KiB pages.