classiccmp(a)u.washington.edu Subj: Re: Mini & Mainframe Power Requirements William Donzelli wrote: <more scary power specs snipped> Well not necessarily. Of late IBM has been putting effort into making S/390 (note: less than 7 years old and not quite a classic) available to small shops: via the P/390 (a 7490 mainframe on a chip hosted by a pentium running OS/2) and the R/390 (also a 7490 with an AIX host - RS/6k or PPC). I must apologize: in a previous message I had referred to the mainframe on a chip as a "3490" which is a tape drive not a CPU model number. To the extent that S/390 derives its heritage from S/370 and S/360 such a box may serve the needs of the mainframe hacker with a small power capacity/budget. IBM's amazing efforts at preservation of backward compatability are a big plus here: to a first approximation S/390 simply adds features to S/370 (the parallel sysplex clustering ability allegedly being quite highly advanced nowadays e.g.). Unfortunately the purchase price won't help the budget minded hacker: a new P/390 runs $50k to $100k and the R/390 a bit more. I've used a P/390 and must say that it is quite a machine: all DASD communication channels are actually handled via a software emulation that runs under the host OS/2 machine, but other than that it seems much like a mainframe. You can run with RAID 0,1,3,5 using PC type drives. The 7490 can run OS/390 (the new name for MVS), VM/ESA, as well as VSE/ESA (the new name for DOS since about 1987). Interestingly enough IBM recently upgraded their P/390 production line to move from 90 MhZ Pentiums to 200 MhZ Pentiums and touted that customers could expect throughput rates to increase a whopping 10% (this gives you an inkling of how much the host OS adds in overhead). According to an IBM technical contact there are shops that are actually running P/390s in a production environment: doing payroll, accounting and whatnot. This despite the fact that the intended market was primarily for software shops porting code to S/390. Perhaps the most unusual thing about S/390 are the OpenEdition environments that run under the various OSes. They give you unix on the mainframe and the OpenEdition environment under OS/390 is now known as "UNIX System Services for OS/390". The irony being that MVS is actually 3-4 years younger than UNIX: UNIX started in 1969, MVS was announced in 1973 and shipped in 1974. At any rate keep an eye out for P/390 on a PC Server 500 (maybe the P90s will wind up on the used market?) and the equivalent R/390 machine - they take only wall plug 110 AC and will let you hack JCL, assembler, and CLISTs to your heart's content - destined to be classics. Peter Prymmer