oft repeated story about mainframe emulation and I/O with regard to 370/158 and integrated channels; most recent telling http://www.garlic.com/~lynn/2007d.html#62 Cycles per ASM instruction
basically the 158 microcode engine had both microcode for emulating 370 and also for emulating channels. in the transition to 303x machines ... the (158) integrated channel microcode was split-off into a dedicated box called the channel director. A 3031 was basically two 158 microcode engines, one with a dedicated engine for running integrated channel microcode and the other engine dedicated to running the 370 emulation microcode (potentially could be considered a two-processor SMP ... which would make a 3031 SMP ... actually four processor system ... since each emulated 370 engine had its corresponding channel director). A 3032 was a repackaged 370/168 with one or more (158 microcode engine integrated channel) "channel directors". A 3033 was 168 wiring diagram mapped to fast chip technology ... along with one or more (158 microcode engine integrated channel) "channel directors" ... i.e. 158 integrated channels supported 6 channels ... to get a 16 channel configuration, you needed three channel directors. A two processor 3033 SMP ... was actually typically an eight processor system ... two 3033 processor with each processor (typically) having three channel directors.
note that splitting off the integrated channel microcode into dedicated processor made the 3031 benchmarks better than 370/158 (even tho the microprocessor engines were the same) ... with 3031 benchmarking almost as fast as 4341 ... the above URL reference also contains results of RAIN benchmark on 158, 3031 and early 4341 engineering machine (ran about 10-15 percent slower than production machines shipped to customers). similarly, 370 115/125 had a memory bus that provided 9 "slots" for up to nine processors. A 115 had a microcode engine running dedicated 370 microcode emulation ... and up to eight other (identical) processors running other microcode loads (communication controller microcode load, disk controller microcode load, etc). A 125 was identical to 115 except the processor engine running 370 microcode emulation was 50percent faster than the other processor engines. recent posts with discussion of 370 115/125 http://www.garlic.com/~lynn/2007d.html#71 Cycles per ASM instruction http://www.garlic.com/~lynn/2007d.html#72 IBM S/360 series operating systems history lots of past posts referring to 303x channel director being dedicated 158 microcode engine with "integrated channel microcode" from 370/158 http://www.garlic.com/~lynn/97.html#20 Why Mainframes? http://www.garlic.com/~lynn/98.html#23 Fear of Multiprocessing? http://www.garlic.com/~lynn/99.html#7 IBM S/360 http://www.garlic.com/~lynn/99.html#176 S/360 history http://www.garlic.com/~lynn/99.html#187 Merced Processor Support at it again http://www.garlic.com/~lynn/2000.html#78 Mainframe operating systems http://www.garlic.com/~lynn/2000c.html#69 Does the word "mainframe" still have a meaning? http://www.garlic.com/~lynn/2000d.html#7 4341 was "Is a VAX a mainframe?" http://www.garlic.com/~lynn/2000d.html#11 4341 was "Is a VAX a mainframe?" http://www.garlic.com/~lynn/2000d.html#12 4341 was "Is a VAX a mainframe?" http://www.garlic.com/~lynn/2000d.html#21 S/360 development burnout? http://www.garlic.com/~lynn/2000g.html#11 360/370 instruction cycle time http://www.garlic.com/~lynn/2001b.html#83 Z/90, S/390, 370/ESA (slightly off topic) http://www.garlic.com/~lynn/2001c.html#3 Z/90, S/390, 370/ESA (slightly off topic) http://www.garlic.com/~lynn/2001c.html#6 OS/360 (was LINUS for S/390) http://www.garlic.com/~lynn/2001i.html#34 IBM OS Timeline? http://www.garlic.com/~lynn/2001j.html#3 YKYGOW... http://www.garlic.com/~lynn/2001j.html#14 Parity - why even or odd (was Re: Load Locked (was: IA64 running out of steam)) http://www.garlic.com/~lynn/2001l.html#24 mainframe question http://www.garlic.com/~lynn/2001l.html#32 mainframe question http://www.garlic.com/~lynn/2002.html#36 a.f.c history checkup... (was What specifications will the standard year 2001 PC have?) http://www.garlic.com/~lynn/2002.html#48 Microcode? http://www.garlic.com/~lynn/2002d.html#7 IBM Mainframe at home http://www.garlic.com/~lynn/2002f.html#8 Is AMD doing an Intel? http://www.garlic.com/~lynn/2002i.html#19 CDC6600 - just how powerful a machine was it? http://www.garlic.com/~lynn/2002i.html#21 CDC6600 - just how powerful a machine was it? http://www.garlic.com/~lynn/2002i.html#23 CDC6600 - just how powerful a machine was it? http://www.garlic.com/~lynn/2002n.html#58 IBM S/370-168, 195, and 3033 http://www.garlic.com/~lynn/2002p.html#59 AMP vs SMP http://www.garlic.com/~lynn/2003.html#39 Flex Question http://www.garlic.com/~lynn/2003g.html#22 303x, idals, dat, disk head settle, and other rambling folklore http://www.garlic.com/~lynn/2003g.html#32 One Processor is bad? http://www.garlic.com/~lynn/2003m.html#31 SR 15,15 was: IEFBR14 Problems http://www.garlic.com/~lynn/2004.html#8 virtual-machine theory http://www.garlic.com/~lynn/2004.html#9 Dyadic http://www.garlic.com/~lynn/2004.html#10 Dyadic http://www.garlic.com/~lynn/2004.html#25 40th anniversary of IBM System/360 on 7 Apr 2004 http://www.garlic.com/~lynn/2004d.html#12 real multi-tasking, multi-programming http://www.garlic.com/~lynn/2004e.html#51 Infiniband - practicalities for small clusters http://www.garlic.com/~lynn/2004f.html#21 Infiniband - practicalities for small clusters http://www.garlic.com/~lynn/2004g.html#17 Infiniband - practicalities for small clusters http://www.garlic.com/~lynn/2004g.html#50 Chained I/O's http://www.garlic.com/~lynn/2004m.html#17 mainframe and microprocessor http://www.garlic.com/~lynn/2004n.html#14 360 longevity, was RISCs too close to hardware? http://www.garlic.com/~lynn/2004o.html#7 Integer types for 128-bit addressing http://www.garlic.com/~lynn/2005b.html#26 CAS and LL/SC http://www.garlic.com/~lynn/2005d.html#62 Misuse of word "microcode" http://www.garlic.com/~lynn/2005e.html#59 System/360; Hardwired vs. Microcoded http://www.garlic.com/~lynn/2005f.html#41 Moving assembler programs above the line http://www.garlic.com/~lynn/2005h.html#40 Software for IBM 360/30 http://www.garlic.com/~lynn/2005m.html#25 IBM's mini computers--lack thereof http://www.garlic.com/~lynn/2005p.html#1 Intel engineer discusses their dual-core design http://www.garlic.com/~lynn/2005q.html#30 HASP/ASP JES/JES2/JES3 http://www.garlic.com/~lynn/2005s.html#22 MVCIN instruction http://www.garlic.com/~lynn/2006m.html#27 Old Hashing Routine http://www.garlic.com/~lynn/2006n.html#16 On the 370/165 and the 360/85 http://www.garlic.com/~lynn/2006o.html#27 oops http://www.garlic.com/~lynn/2006q.html#31 VAXen with switchmode power supplies? http://www.garlic.com/~lynn/2006r.html#34 REAL memory column in SDSF http://www.garlic.com/~lynn/2006r.html#40 REAL memory column in SDSF http://www.garlic.com/~lynn/2006s.html#40 Ranking of non-IBM mainframe builders? http://www.garlic.com/~lynn/2006s.html#42 Ranking of non-IBM mainframe builders? http://www.garlic.com/~lynn/2006t.html#19 old vm370 mitre benchmark http://www.garlic.com/~lynn/2007b.html#18 How many 36-bit Unix ports in the old days? http://www.garlic.com/~lynn/2007d.html#21 How many 36-bit Unix ports in the old days?
