The Molecular was an 18 bit, dual accumulator, programmable computer, with a typical minicomputer architecture.
The Molecular could address up to 64K words of memory. In later models, memory extensions were made available by the use of bank switching. The top 32K memory could be switched between four banks, giving an overall memory limit of 160K words. There was a complex (for the time) instruction set, a simple interrupt system, multiple input/output ports, and Direct Memory Access or Data Channel for high speed peripherals.
No industry standard operating system was supported, but in later years an standard control program was installed on all machines. The control programs produced, LOS and OS, gave the machine it's multi-user function. Note that the task scheduling was co-operative, pre-emptive multi-tasking was never developed.
There was a gradual progression in the models available, although the basic instruction set didn't change over the years. (Actually the Mk 1 machines didn't support multiple shift and rotate instructions.)
The primary use for the Molecular was in commercial systems, particular distribution companies - hence the name change to Distributor - one of which is shown alongside.