A multi-function FASTBUS front-end for VAXBI computers

A versatile and high-performance interface between DEC computers based on VAXBI and FASTBUS has been designed to couple a general-purpose FASTBUS master with a specially developed intelligent module. The hardware capabilities of the interface are discussed, with particular reference to the Aleph event builder (AEB), which is a single-width FASTBUS card based on the MC68020 CPU and the MC68881 floating-point coprocessor, and the AEB-VAX interface. The software, as implemented in the Aleph experiment at the LEP (Large Electron Position) collider, is presented, covering the communication protocol, the software for the high-speed interface to the DEC DRB32 BI adapter, the AEB software, and the VAX software. The results of a performance evaluation for single-word and block transfer actions are presented.<
>