Traffic Service Position System No. 1B: Hardware configuration

The Traffic Service Position System No. 1B (TSPS No. 1B) was developed by replacing the Stored Program Control No. 1A (SPC 1A) with the SPC 1B, consisting of a 3B20 Duplex Processor (3B20D) and a Peripheral System Interface (PSI). The PSI was designed to interface the 3B20D Processor technology with the existing TSPS peripheral system. This article describes the differences in technologies between the SPC 1A and SPC 1B, the hardware design required to overcome these differences, and the fault recovery and diagnostic software development required to integrate the new hardware into the maintenance structure of the TSPS No. 1B.