Going from memory this is one of the add ons for the Anritsu spectrum analyser range. The slots were for 'personality' modules that added functions to the basic analyser and the disk drive was for data logging. I used Anritsu analysers quite a bit. They were, at only twice the cost of the Landrover Discovery I used to carry them around in, a lot cheaper than the HP equivalents. Can't remember if the slots were PCMCIA or not. Lee. . Send instant messages to your online friends http://uk.messenger.yahoo.com