Hi, HP3000-L listers ! OK, there seems to have been some confusion about the numbering conventions used for MPE/iX releases. I will try to sort things out. Maybe CSY folks on the list have more ideas, but let's get down with a starter . First, the RELEASE v.u.f has been different from the MPE/iX v.u.f for some years, now. You can view MPE/iX as being only a component of the whole release . Second, there's been a numbering convention, also for some years, that mandates a x.0 number for PUSH (Platform) releases, and something different for PULL releases. That's why we had 4.0 and 5.0 as PUSH releases and 4.5 and 5.5 as PULL releases. If we get deeper in the past, we will begin to find different conventions . Third, the first letter of the RELEASE v.u.f (not the MPE/iX v.u.f !!!) has been used to designate major rewrites of the OS. A was for the "first-generation" OS, B was used for multiprocessor-capable releases, and now we have C for POSIX-compliant releases. Conventional wisdom would mandate that this convention be used for both the RELEASE and the MPE/iX v.u.fs, but, for POSIX, MPE/iX has taken some time to catch up with the release v.u.f. That's why 5.0 has a release v.u.f of C.50.00, but an MPE/iX v.u.f of B.79.06 . Fourth, the "commercial" denomination for a given release is carried by the release v.u.f, not by the MPE/iX v.u.f. The MPE/iX v.u.f is simply the number used by the lab to build the OS. It has no meaningful value outside the lab. More to the point, we use the "u" part of the release v.u.f to carry the release name. As an example, let's remember that 4.0 was release B.40.00. The "u" part of the v.u.f is 40, you just insert a period, and there you go ... 4.0 !!! You have the same with B.30.00 for 3.0, B.31.00 for 3.1, C.45.00 for 4.5, C.50.00 for 5.0 and now C.55.00 for 5.5. If no major rewrite occurs, 6.0 should be C.60.00 when it comes out . The following table should make things clearer ... well, hopefully ... Commercial Release MPE/iX release name v.u.f v.u.f 3.0 B.30.00 B.08.14 First multiprocessor capable version 3.1 B.31.00 B.09.66 Introduced 9x7 boxes and SCSI 4.0 B.40.00 B.30.45 Introduced 4-way MPs and Emeralds 4.5 C.45.00 B.57.06 Introduced Posix 5.0 C.50.00 B.79.06 Introduced 9x9s, among others 5.5 C.55.00 C.05.08 Introduced network printing, and many others OK, that was my $.02 about release naming and numbering conventions currently used for MPE/iX. Maybe CSY people on the list can add other ideas . In any case, feel free to e-mail me privately if you'd like more about the subject . Christian Lheureux Software Support and Services Organization Hewlett-Packard France [log in to unmask] Disclaimer : These were my own opinions, not necessarily my employer's, much less anybody else's !