Esso chose to sign a UKP4m systems integration deal with Marlow based software house Topas UK Ltd at the one-man computer show: the deal will enable Esso to computerise its 25 authorised UK distributors, and will use order processing, administration, marketing and accounting software developed by Topas for the AS/400 range; for its part, IBM has supplied Topas with 25 AS/400 Model B30s, together with a Model B40 to oversee operations and link back to the Esso mainframe, based at corporate headquarters in Oxfordshire.