It did this by using a modified ALGOL compiler (the only programming language supported by Dijkstra's system) to "automatically generate calls to system routines, which made sure the requested information was in memory, swapping if necessary".
[3] Paged virtual memory was also used for buffering input/output (I/O) device data, and for a significant portion of the operating system code, and nearly all the ALGOL 60 compiler.
This division of the kernel into layers was similar in some ways to Multics' later ring-segmentation model.
The code of the system was written in assembly language for the Dutch Electrologica X8 computer.
This computer had a word size of 27 bits, 48 kilowords of core memory,[3] 512 kilowords of drum memory providing backing store for the LRU cache algorithm, paper tape readers, paper tape punches, plotters, and printers.