prestel computers were based on gec 4000 series " minicomputer " with small differences in the accumulation according to the function of the machine. irc main machines were originally gec 4082 equipped with 384 kbytes memory core store machines, six 70 mbyte hdd and 100 ports for 1500 initial users. the network grew to the point that in june 1980 there were four stand-alone retrieval computers in the london area with six other computers installed in pairs in birmingham, edinburgh and manchester. the ten computers could output to approximately 1000 user ports, expandable to 2000. the gec 4082 computer with 512 megabyte capacity will interconnect to the 10 and later to 20 retrieval computers to handle the data files. the initial data base consists of approximately 164,000 information pages (june, 1980) with planned update capacity of 260,000 pages. a page consists of a maximum of 960 data characters (5x7 bits each, suggesting approximately 35,000 bits per page).