Experience Using the 168/E Microprocessor for off-Line Data Analysis

The 168/E is a SLAC developed microprocessor which emulates the IBM 360/370 computers with an execution speed of about one half of a IBM 370/168. These processors are used in parallel for the track finding and geometry programs of the LASS spectrometer. The system is controlled by a PDP-11 minicomputer via a three port interface which we call the Bermuda Triangle. The tape handling and downloading is controlled by one of SLAC´s IBM computers via a SLAC built interface between the PDP-11 and an IBM channel. Initially, there will be a system of 6 168/E´s which should be able to give six times the production capacity than can be attained by running production jobs on the SLAC Triplex system. The cost of the system, including the channel interface, is $120,000 and yet it yields the equivalent computer power of 3 IBM 370/168´s. Hence, this system is an extremely cost-effective method for off-line data analysis.