<div class="htmlview paragraph">The first SUMITOMO ELECTRONIC ANTILOCK SYSTEM (ALS), a 4-Sensor 3-Channel System for sophisticated FWD vehicles, has been in production since 1987. Further developments have lead to systems suitable for 4W vehicles and compact cars, showing increased control quality and reduced size, weight and production cost.</div> <div class="htmlview paragraph">Reliability, one of the major targets in the development of the First system's Electronic Control Unit (ECU) since 1982, was successfully achieved. Recent work has been geared toward reducing the size and production cost of ECU hardware, whilst maintaining the system's reliability.</div> <div class="htmlview paragraph">This paper describes the basic design of the current 1987 ECU and further details developments of the hardware.</div>