Fear, Uncertainty & Doubt rear their ugly heads again as rumours multiply that IBM is nearly ready with an MVS/XB successor to XA for launch next year: key point about the new operating system is that it will run only on the 3090s, the intention being finally to ob-solete all those stubborn 308X machines that so many users still find more than adequate for their needs; from what Computerwoche hears, as well as extending the real address space yet again from the present 2Gb, MVS/XB will include improved input-output subsystem and support for larger cache.