The invention concerns a high storage capacity ROM-RAM disk and a process for reading and writing to the ROM-RAM disk. T he aim of the invention is to devise a ROM-RAM disk and a process making it possible to read ROM and RAM simultaneously, to read the ROM area and at the same time write to the RAM area and to provide the largest possible volume of memory. The invention comprises two alternative designs. In a first design a ROM-RAM disk contains an area having both ROM and RAM memory structures as of a certain radius or diameter, establishing therein, at a constant rotational speed, a scanning/writing speed which ensures a reading/separation of the data stored in the ROM-RAM structures. In a second design, the available storage area is taken up entirely by a ROM-RAM storage area, where RAM memory structures have a reduced data rate in order to form, a length of memory structures necessary for separating the data stored in the ROM-RAM storage area.