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XEtOX eDD ARCHIVES 1 haVi read and underBtoo4 XEROX BUSINESS SYSTEMS Pages _ _ _ _- To Reviewer_ _--Da.t\jj-~- ---===- Systems Development Department 'f: of pages Ref . .?a=,s lJjj -1.$1 . July 7, 1978 To: Dave Liddle From: Peter Bishop / SD at Palo Alto Subject: A new class of I/O device: the OIS archive device. Copies: W. Lynch, J. Weaver, J. Wick, S. Wallace, R. Sonderegger, R. Metcalfe, W. Kennedy, J. White, V. Schwartz, R. Belleville, T. Townsend, J. Mendelson, R. Wickham, C. Irby, L. Bergsteinsson, W. Bewley, J. Szelong, P. Heinrich, E. Harslem, L. Clark, D. DeSantis, J. Reiley, G. LeCesne, D. Reilly, Dave TIlOrnburg, Brian Rosen, Bill Gunning Introduction Developments in LSI technology will have important effects on the cost of memory, and therefore upon the architectures of computers in the 1980s. Many people who try to predict what computer architectures will exist in the 1980s ignore the huge cost of developing software for drastically new architectures. This note assumes that basic computer architectures will not change, i.e. that the DO will be a state-of-the-art processor (in the low-moderate price range). It is relalively clear that in the 1980s there will be two major factors in the cost of a computer system: peripherals and memory. Therefore the cost of memory can be expected to affect the system architecture. A recent report by Mackintosh Consultants Co. Ltd. [1] has taken a close look at the costs of memory in many different technologies. Using this report, we can estimate what technologies we will be using for memory in the 1980s. An important factor that cannot be ignored is the effect of price competition from new memory technologies (such as bubble memory and CCDs) on the structure and price of old, established memory technologies (such as disk). One conclusion of the Mackintosh report is that there is no future for fixed head disk technology because by 1985 bubble memories and CCDs will be cheaper while offering a faster access time than fixed head disks. Mackintosh further predicts that beginning in 1980 bubble and CCD memories wUl be marginally cheaper than RAM, but by 1985 bubble memories will be one order of magnitude cheaper than RAM. The 1985 cost of bubble memories, however, will still be twice as expensive as current costs for non-removable moving head disks. Mackintosh expects the cost of non- removable moving head disks to drop to one-third of their present cost by 1980. An int