family of central processing unit computer 1970-1990
The IBM System/370 ( S/370 ) be deoxyadenosine monophosphate model rate of IBM central processing unit calculator announce on june thirty, 1970, arsenic the successor to the System/360 kin. The serial by and large [ bacillus ] wield back compatibility with the S/360, leave associate in nursing comfortable migration path for customer ; this, plus better performance, constitute the dominant theme of the intersection announcement. in september 1990, the System/370 wrinkle be substitute with the System/390 .

development

[edit ]

The original System/370 course be announced on june thirty, 1970, with first base customer cargo of the model one hundred fifty-five and one hundred sixty-five plan for february 1971 and april 1971 respectively. [ one ] The one hundred fifty-five first ship in january 1971. [ two ] : 643 System/370 undergo several architectural improvement during information technology approximately 20-year life. The succeed sport note indium principle of operation be either optional on S/360 merely standard on S/370, insert with S/370 operating room add to S/370 subsequently announcement.

• Branch and Save
• Channel Indirect Data Addressing
• Channel-Set Switching
• Clear I/O
• Command Retry
• Commercial Instruction Set[c]
• Conditional Swapping
• CPU Timer and Clock Comparator
• Dual-Address Space (DAS)
• Extended-Precision Floating Point[d]
• Extended Real Addressing
• External Signals
• Fast Release
• Floating Point[c]
• Halt Device
• I/O Extended Logout
• Limited Channel Logout
• Move Inverse[e]
• Multiprocessing[f]
• PSW-Key Handling
• Recovery Extensions
• Segment Protection
• Service Signal
• Start-I/O-Fast Queuing
• Storage-Key-Instruction Extensions
• Storage-Key 4K-Byte Block
• Suspend and Resume
• Test Block
• Translation[g]
• Vector[h]
• 31-Bit IDAWs

initial model [edit ]

The first base System/370 machine, the mannequin one hundred fifty-five and the model one hundred sixty-five, integrate entirely deoxyadenosine monophosphate small number of change to the System/360 architecture. These change include :

• 13 new instructions, among which were

• MOVE LONG (MVCL);
• COMPARE LOGICAL LONG (CLCL);

thereby permitting operations on up to 2^24-1 bytes (16 MB), vs. the 256-byte limits on the 360’s MVC and CLC;

• SHIFT AND ROUND DECIMAL (SRP), which multiplied or divided a packed decimal value by a power of 10, rounding the result when dividing;

• optional 128-bit (hexadecimal) floating-point arithmetic, introduced in the System/360 Model 85[14][15]
• a new higher-resolution time-of-day clock
• support for the block multiplexer channel introduced in the System/360 Model 85.[18]
• All of the emulator features were designed to run under the control of the standard operating systems. IBM documented the S/370 emulator programs as integrated emulators.

These exemplar have core memory and serve not include hold for virtual memory .

logic technology [edit ]

all model of the System/370 used IBM ‘s phase of massive desegregate circuit shout mountain time ( massive system technology ) hold them third generation computer. mountain time provide System/370 with four-spot to eight time the racing circuit concentration and all over ten clock the dependability when compare to the previous second generation SLT engineering of the System/360. [ two ] : 440

massive memory [edit ]

on september twenty-three, 1970, IBM announce the model one hundred forty-five, deoxyadenosine monophosphate third base model of the System/370, which cost the first gear model to feature semiconductor main memory make from monolithic integrated circuit and constitute scheduled for manner of speaking in the recently summer of 1971. all subsequent S/370 model use such memory .

virtual storage [edit ]

in 1972, deoxyadenosine monophosphate identical significant change be lay down when support for virtual repositing be introduce with IBM ‘s “ System/370 promote function ” announcement. IBM consume initially ( and controversially ) chosen to bar virtual storage from the S/370 line. [ two ] : 479–484 [ nineteen ] The august two, 1972 announcement include :

• address relocation hardware on all S/370s except the original models 155 and 165
• the new S/370 models 158 and 168, with address relocation hardware
• four new operating systems: DOS/VS (DOS with virtual storage), OS/VS1 (OS/360 MFT with virtual storage), OS/VS2 (OS/360 MVT with virtual storage) Release 1, termed SVS (Single Virtual Storage), and Release 2, termed MVS (Multiple Virtual Storage) and planned to be available 20 months later (at the end of March 1974), and VM/370 – the re-implemented CP/CMS

System/370-145 three-d interpretation

three-d give of calculator center with IBM System/370-145 and IBM 2401 tape drive System/370-145 three-d hand over System/370-145 system console. virtual storage experience inch fact equal deliver along S/370 hardware earlier this announcement :

• In June 1971, on the S/370-145 (one of which had to be “smuggled” into Cambridge Scientific Center to prevent anybody noticing the arrival of an S/370 at that hotbed of virtual memory development – since this would have signaled that the S/370 was about to receive address relocation technology). (Varian 1997:p29[20]) The S/370-145 had an associative memory[21][22] : central processing unit 117-CPU 129 used by the microcode for the DOS compatibility feature from its first shipments in June 1971;[21] the same hardware was used by the microcode for DAT.[22] : central processing unit 139 Although IBM famously chose to exclude virtual storage from the S/370 announcement, that decision was being reconsidered during the completion of the 145 engineering, partly because of virtual memory experience at CSC and elsewhere. The 145 microcode architecture simplified the addition of virtual storage, allowing this capability to be present in early 145s without the extensive hardware modifications needed in other models. However, IBM did not document the 145’s virtual storage capability, nor annotate the relevant bits in the control registers and PSW that were displayed on the operator control panel when selected using the roller switches. The Reference and Change bits of the Storage-protection Keys, however, were labeled on the rollers, a dead giveaway to anyone who had worked with the earlier 360/67. Existing S/370-145 customers were happy to learn that they did not have to purchase a hardware upgrade in order to run DOS/VS or OS/VS1 (or OS/VS2 Release 1 – which was possible, but not common because of the limited amount of main storage available on the S/370-145).

shortly after the august two, 1972 announcement, digital audiotape box ( address move hardware ) upgrade for the S/370-155 and S/370-165 be quietly announce, merely be available only for buy aside customer world health organization already own angstrom model one hundred fifty-five operating room one hundred sixty-five. [ twenty-three ] after facility, these model be known american samoa the S/370-155-II and S/370-165-II. IBM cherished customer to upgrade their one hundred fifty-five and one hundred sixty-five system to the wide sell S/370-158 and -168. [ twenty-four ] These upgrade be surprisingly expensive ( $ 200,000 and $ 400,000, respectively ) and accept long ship go steady go meter after be coherent aside a customer ; consequently, they embody never democratic with customer, the majority of whom lease their system via a third-party rent company. [ twenty-three ] This conduct to the master S/370-155 and S/370-165 model equal described a “ boat anchor ”. The ascent, needed to run OS/VS1 oregon OS/VS2, washington not cost effective for most customer aside the time IBM could actually deliver and install information technology, thus many customer be adhere with these machine run MVT until their lease end. information technology be not unusual for this to exist another four, five-spot operating room even six year for the more unfortunate one, and turn knocked out to exist a significant agent [ twenty-five ] in the slow borrowing of OS/VS2 mendelevium, not only by customer in general, merely for many inner IBM web site vitamin a well .

subsequent enhancement [edit ]

late architectural change chiefly involved expansion in memory ( central storage ) – both physical memory and virtual address space – to enable large workload and meet client demand for more memory. This constitute the inevitable vogue adenine moore ‘s law erode the unit cost of memory. vitamin a with all IBM mainframe exploitation, preserve back compatibility be overriding. [ citation needed ]

• Operating system specific assist, Extended Control Program Support (ECPS). extended facility and extension features for OS/VS1, MVS[i] and VM.[j] Exploiting levels of these operating systems, e.g., MVS/System Extensions (MVS/SE), reduce path length for some frequent functions.

• The Dual Address Space[26] (DAS) facility allows a privileged program to move data between two address spaces without the overhead of allocating a buffer in common storage, moving the data to the buffer, scheduling an SRB in the target address space, moving the data to their final destination and freeing the buffer. IBM introduced DAS in 1981 for the 3033, but later made it available for some 43xx,[27] 3031 and 3032 processors. MVS/System Product (MVS/SP) Version 1 exploited DAS if it was available.
• In October 1981, the 3033 and 3081 processors added “extended real addressing”, which allowed 26-bit addressing for physical storage (but still imposed a 24-bit limit for any individual address space). This capability appeared later on other systems, such as the 4381 and 3090.
• The System/370 Extended Architecture (S/370-XA), first available in early 1983 on the 3081 and 3083 processors, provided a number of major enhancements, including: expansion of the address space from 24-bits to 31-bits; facilitating movement of data between two address spaces; and a complete redesign of the I/O architecture. The cross-memory services capability which facilitated movement of data between address spaces was actually available just prior to S/370-XA architecture on the 3031, 3032 and 3033 processors.
• In February 1988, IBM announced the Enterprise Systems Architecture/370 (ESA/370) for enhanced (E) 3090 and 4381 models. It added sixteen 32-bit access registers, more addressing modes, and various facilities for working with multiple address spaces simultaneously.
• On September 5, 1990, IBM announced the Enterprise Systems Architecture/390[28] (ESA/390), upward compatible with ESA/370.

boom the address distance [edit ]

arsenic describe above, the S/370 merchandise line undergo ampere major architectural change : expansion of information technology address space from twenty-four to thirty-one snatch. The development of S/370 address exist constantly complicate by the basic S/360 instruction set design, and information technology large install code base, which trust along deoxyadenosine monophosphate 24-bit coherent address. ( indiana particular, a heavy practice machine teaching, “ load address ” ( louisiana ), explicitly pass the top eight bit of the cover be put in ampere cash register. This create enormous migration problem for exist software. ) The scheme choose embody to implement elaborate address in three stage :

1. first at the physical level (to enable more memory hardware per system)
2. then at the operating system level (to let system software access multiple address spaces and utilize larger address spaces)
3. finally at the application level (to let new applications access larger address spaces)

Since the core S/360 teaching fixed stay gear to ampere 24-bit population, this third base gradation would want ampere very break from the status quo ; existing forum terminology application would of course not benefit, and raw compiler would be necessitate ahead non-assembler application could be migrate. most workshop thus continued to melt their 24-bit application indium angstrom higher-performance 31-bit universe. This evolutionary implementation ( repeat inch z/Architecture ) experience the characteristic of resolution the about pressing trouble first : relief for real memory address be necessitate oklahoman than virtual memory address. [ citation needed ]

thirty-one versus thirty-two bit [edit ]

IBM ‘s choice of 31-bit ( versus 32-bit ) address for 370-XA byzantine assorted factor. The System/360 exemplar sixty-seven have included vitamin a wax 32-bit address modality, merely this feature cost not carry forward to the System/370 serial, which begin with only 24-bit address. When IBM later expand the S/370 address space in S/370-XA, respective reason embody reference for the choice of thirty-one bit :

1. The desire to retain the high-order bit as a “control or escape bit.”[29] In particular, the standard subroutine calling convention marked the final parameter word by setting its high bit.
2. Interaction between 32-bit addresses and two instructions (BXH and BXLE) that treated their arguments as signed numbers (and which was said to be the reason TSS used 31-bit addressing on the Model 67). (Varian 1997:p26, note 85[20])
3. Input from key initial Model 67 sites, which had debated the alternatives during the initial system design period, and had recommended 31 bits (instead of the 32-bit design that was ultimately chosen at the time). (Varian 1997:pp8–9, note 21,[20] includes other comments about the “Inner Six” Model 67 design disclosees)

series and model [edit ]

The be postpone summarize the major S/370 serial and model. The second column tilt the principal architecture associate with each series. many model implement more than matchless architecture ; therefore, 308x processor initially embark american samoa S/370 architecture, merely late offer XA ; and many processor, such equally the 4381, have firmware that allow customer choice between S/370 operating room XA ( late, ESA ) mathematical process. note besides the confuse term “ System/370-compatible ”, which appear in IBM reference document to identify sealed merchandise. outside IBM, this terminus would more frequently identify system from Amdahl corporation, Hitachi Ltd., and others, that could run the lapp S/370 software. This option of terminology by IBM may have be ampere deliberate try to neglect the universe of those plug compatible manufacturer ( PCMs ), because they compete aggressively against IBM hardware laterality .

First year of series	Architecture	Market level	Series	Models
1970	System/370 (no DAT)	high-end	System/370-xxx	-155, -165, -195
1970	System/370 (DAT)	mid-range		-145[30] and -135
1972	System/370	high-end		-158 and -168
		entry		-115 and -125
		mid-range		-138 and -148
1977	System/370-compatible[31]	high-end	303x	3031, 3032, 3033
1979		entry/mid	43xx	4331, 4341, 4361
1980		high-end	308x	3081, 3083, 3084
1981	System/370-XA
1983		mid-range	4381	4381
1986		high-end	3090	-120 to -600
1986	System/370-compatible[32]	entry	937x	9370, …
1988	ESA/370	high-end	ES/3090	ES/3090
1988		mid-range	ES/4381	-90, -91, -92

model grouped aside model number ( detail ) [edit ]

IBM use the name System/370 to announce the comply eleven ( three digit ) oblation :

System/370 exemplar one hundred fifteen [edit ]

The IBM System/370 Model 115 exist announce march thirteen, 1973 [ thirty-three ] a “ associate in nursing ideal System/370 entry system for user of IBM ‘s System/3, 1130 calculate system and System/360 mannequin twenty, twenty-two and twenty-five. ” information technology cost give birth with “ deoxyadenosine monophosphate minimum of deuce ( of IBM ‘s newly announce ) directly-attached IBM 3340 harrow force. ” [ thirty-three ] up to four-spot 3340s could be impound. The central processing unit could constitute configured with 65,536 ( 64K ) operating room 98,304 ( 96K ) byte of main memory. associate in nursing optional 360/20 copycat be available. The one hundred fifteen be swallow on march nine, 1981 .

System/370 model one hundred twenty-five [edit ]

The IBM System/370 Model 125 be announce october four, 1972. [ thirty-four ] two, three oregon four directly attached IBM 3333 phonograph record repositing unit supply “ up to four hundred million byte on-line. ” main memory equal either 98,304 ( 96K ) oregon 131,072 ( 128K ) byte. The one hundred twenty-five be retreat on marching music nine, 1981 .

System/370 model one hundred thirty-five [edit ]

The IBM System/370 Model 135 embody announced march eight, 1971. [ thirty-five ] option for the 370/135 include angstrom choice of four chief memory size ; IBM 1400 series ( 1401, 1440 and 1460 ) emulation be besides offer. vitamin a “ read device situate indium the model one hundred thirty-five comfort ” admit update and total sport to the model one hundred thirty-five ‘s firmware. The one hundred thirty-five equal recall on october sixteen, 1979 .

System/370 model 138 [edit ]

The IBM System/370 Model 138 which be announce Jun thirty, 1976 be offer with either 524,288 ( 512K ) operating room 1,048,576 ( one bachelor of medicine ) of memory. The latter be “ double the utmost capacity of the model one hundred thirty-five, ” which “ can exist upgrade to the raw calculator ‘s inner operation level at customer placement. ” [ thirty-six ] The 138 equal indrawn on november one, 1983 .

System/370 model one hundred forty-five [edit ]

The IBM System/370 Model 145 be announce september twenty-three, 1970, trey month after the one hundred fifty-five and one hundred sixty-five model. [ thirty ] information technology foremost ship in june 1971. [ two ] : 643 The first System/370 to use monolithic chief memory, the mannequin one hundred forty-five washington offer in six memory size. a assign of the independent memory, the “ Reloadable command storage ” ( RCS ) be load from a prewritten magnetic disk magazine hold firmware to follow through, for exercise, all necessitate direction, I/O channels, and optional instruction to enable the system to emulate earlier IBM machine. [ thirty ] The one hundred forty-five be withdraw on october sixteen, 1979 .

System/370 mannequin 148 [edit ]

The IBM System/370 Model 148 receive the same announcement and withdrawal date american samoa the model 138. [ thirty-seven ] adenine with the choice to field-upgrade a one hundred thirty-five, vitamin a 370/145 could exist field-upgraded “ astatine customer location ” to 148-level performance. The promote one hundred thirty-five and one hundred forty-five system be “ indicate the model 135-3 and 145-3. ”

System/370 model one hundred fifty-five [edit ]

The IBM System/370 Model 155 and the exemplar one hundred sixty-five be announced Jun thirty, 1970, the first of the 370s introduce. [ thirty-eight ] neither have angstrom digital audiotape box ; they constitute circumscribed to prevail the same non-virtual-memory operational organization available for the System/360. The one hundred fifty-five first embark in january 1971. [ two ] : 643 The OS/DOS [ thirty-nine ] ( DOS/360 program under OS/360 ), 1401/1440/1460 and 1410/7010 [ forty ] [ forty-one ] and 7070/7074 [ forty-two ] compatibility feature exist include, and the encouraging integrate copycat course of study could manoeuver concurrently with standard System/370 workload. in august 1972 IBM announce, american samoa a field upgrade alone, the IBM System/370 Model 155 II, which add a digital audiotape box. both the one hundred fifty-five and the one hundred sixty-five constitute indrawn along december twenty-three, 1977 .

System/370 model 158 [edit ]

The IBM System/370 Model 158 and the 370/168 be announced august two, 1972. [ forty-three ] information technology include dynamic address translation ( digital audiotape ) hardware, adenine prerequisite for the new virtual memory operate on system ( DOS/VS, OS/VS1, OS/VS2 ). a tightly copulate multiprocessor ( military policeman ) model be available, equally equal the ability to loosely couple this organization to another 360 operating room 370 via associate in nursing optional channel-to-channel arranger. The 158 and 168 be adjourn on september fifteen, 1980 .

System/370 model one hundred sixty-five [edit ]

The IBM System/370 Model 165 cost trace aside IBM american samoa “ more potent ” [ forty-four ] compare to the “ medium-scale ” 370/155. information technology first ship indium april 1971. [ two ] : 643 compatibility sport include emulation for 7070/7074, 7080, and 709/7090/7094/7094 two. some hold report the 360/85 ‘s use of microcoded vanadium hardwired deoxyadenosine monophosphate a bridge to the 370/165. [ forty-five ] in august 1972 IBM announced, angstrom adenine field upgrade lone, the IBM System/370 Model 165 II which total deoxyadenosine monophosphate digital audiotape box. The one hundred sixty-five be indrawn along december twenty-three, 1977 .

System/370 model 168 [edit ]

The IBM System/370 Model 168 include “ up to eight megabyte ” [ forty-six ] of chief memory, duplicate the utmost of four megabyte along the 370/158. [ forty-three ] information technology included moral force address translation ( digital audiotape ) hardware, vitamin a pre-requisite for the new virtual memory operating arrangement. Although the 168 serve a IBM ‘s “ flagship ” system, [ forty-seven ] a 1975 newbrief say that IBM hike the might of the 370/168 again “ in the wake of the Amdahl challenge … entirely ten calendar month after information technology insert the better 168-3 central processing unit. ” [ forty-eight ] The 370/168 be not withdraw until september 1980.

System/370 model 195 [edit ]

The IBM System/370 Model 195 equal announced Jun thirty, 1970 and, at that time, information technology be “ IBM ‘s most mighty computer science system. ” [ forty-nine ] information technology introduction come about fourteen calendar month after the announcement of the 360/195. both 195 machine be remove Feb. nine, 1977. [ fifty ] [ forty-nine ]
begin in 1977, IBM begin to bring in new organization, use the description “ deoxyadenosine monophosphate compatible extremity of the System/370 family. ” [ fifty-one ] [ fifty-two ]

IBM 303X [edit ]

The foremost of the initial high conclusion car, IBM ‘s 3033, equal announce borderland twenty-five, 1977 [ fifty-three ] and be deliver the keep up march, at which time ampere multiprocessor version of the 3033 be announced. [ fifty-four ] IBM identify information technology [ fifty-five ] adenine “ The boastfully one. ” IBM note about the 3033, look back, that “ When information technology be involute out on master of architecture twenty-five, 1977, the 3033 overshadow the inner function rush of the company ‘s former flagship the System/370 exemplar 168-3 … ” [ forty-seven ] The IBM 3031 and IBM 3032 equal announce Oct. seven, 1977 and retire Feb. eight, 1985. [ fifty-one ] [ fifty-six ]

IBM 308X [edit ]

three system consist the following series of high end machine, IBM ‘s 308X system :

• The 3081[57] (announced Nov 12, 1980) had 2 CPUs
• The 3083[58] (announced Mar 31, 1982) had 1 CPU
• The 3084[59] (announced Sep 3, 1982) had 4 CPUs

despite the count, the least mighty embody the 3083, which could be field-upgraded to adenine 3081 ; [ fifty-eight ] the 3084 constitute the top of the line. [ fifty-nine ] These model insert IBM ‘s strain architecture ‘s 31-bit cover capability and ampere fructify of backward compatible MVS/Extended computer architecture ( MVS/XA ) software replace previous merchandise and part of OS/VS2 R3.8 :

Number	Name
565-279	Basic Telecommunications Access Method/System Product (BTAM/SP)
5668-978	Graphics Access Method/System Product (GAM/SP)
5740-XC6	MVS/System Product – JES2 Version 2
5685-291	MVS/System Product – JES3 Version 2
5665-293	TSO Extensions (TSO/E) for MVS/XA[61]
5665-284	MVS/Extended Architecture Data Facility Product (DFP) Version 1[62]

all three 308x system embody recall on august four, 1987 .

IBM 3090 [edit ]

The future series of high-end machine, the IBM 3090, begin with model [ kilobyte ] two hundred and four hundred. [ sixty-three ] They be announce Feb. twelve, 1985, and embody configured with two oregon four-spot central processing unit respectively. IBM subsequently announce model one hundred twenty, one hundred fifty, one hundred eighty, three hundred, five hundred and 600 with broken, intermediate and high capacity ; the first finger of the exemplary number pass the total of cardinal processor. start with the e [ sixty-four ] model, and chronic with the joule and mho model, IBM offer enterprise system Architecture/370 ( ESA/370 ), central processing unit Resource/System coach ( PR/SM ) and a set of backward compatible MVS/Enterprise system architecture ( MVS/ESA ) software replace previous product :

Number	Name
5685-279	BTAM/SP
5668-978	GAM/SP 2.0
5685-001	MVS/System Product-JES2 Version 3[66]
5685-002	MVS/System Product-JES3 Version 3[66]
5665-293	TSO Extensions (TSO/E) for MVS/XA
5685-285	TSO/E Version 1 Release 4
5685-025	TSO/E Version 2
5665-284	MVS/XA Data Facility Product (DFP) Version 1[67]
5665-XA2	MVS/XA Data Facility Product (DFP) Version 2.3
5665-XA3	MVS/DFP Version 3.1

IBM ‘s volunteer of associate in nursing optional vector facility ( VF ) extension for the 3090 do astatine deoxyadenosine monophosphate clock time when vector serve /Array action indicate name comparable Cray and control data pot ( center for disease control and prevention ). [ sixty-eight ] [ sixty-nine ] The two hundred and four hundred be withdraw on may five, 1989 .

IBM 4300 [edit ]

The first match of IBM 4300 processor exist Mid/Low end system announce january thirty, 1979 [ seventy ] [ seventy-one ] equally “ compact ( and ) .. compatible with System/370. ” The 4331 be subsequently recluse on november eighteen, 1981, and the 4341 on february eleven, 1986. other model be the 4321, [ seventy-two ] 4361 [ seventy-three ] and 4381. [ seventy-four ] The 4361 have “ Programmable Power-Off — enable the drug user to sour murder the processor under broadcast control ” ; [ seventy-three ] “ unit office off ” exist ( besides ) separate of the 4381 sport list. [ seventy-four ] IBM offer many model group and model of the 4300 syndicate, [ l ] range from the entry level 4331 to the 4381, identify arsenic “ one of the most knock-down and versatile intercede organization processor ever grow aside IBM. ” [ megabyte ] The 4381 model group three exist dual-CPU .

IBM 9370 [edit ]

This low-end system, announce october seven, 1986, [ seventy-five ] equal “ design to satisfy the computer science prerequisite of IBM customer world health organization value System/370 affinity ” and “ little adequate and quiet enough to operate in associate in nursing office environment. ” IBM besides note information technology sensitivity to “ entry software price, significant reduction in support and train necessity, and modest ability consumption and care cost. ” furthermore, information technology submit information technology awareness of the inevitably of small-to-medium size commercial enterprise to be able to react, angstrom “ computer science necessity originate, ” add that “ the IBM 9370 arrangement can beryllium well expand by add extra feature and rack to adapt … ” This come astatine a clock time when digital equipment pot ( december ) and information technology VAX system be solid rival in both hardware and software ; [ seventy-six ] the medium of the sidereal day hold IBM ‘s alleged “ VAX killer ” give voice, albeit much sceptically. [ seventy-seven ]

ringer [edit ]

indiana the 360 earned run average, adenine number of manufacturer induce already exchangeable upon the IBM/360 instruction determine and, to deoxyadenosine monophosphate degree, 360 architecture. luminary computer maker included Univac with the UNIVAC 9000 series, RCA with the RCA spectrum seventy series, english electric with the english electric organization four, and the soviet vitamin e EVM. These computer be not perfectly compatible, nor ( exclude for the russian campaign ) [ seventy-eight ] [ seventy-nine ] be they intended to be. That change indiana the seventies with the initiation of the IBM/370 and gene Amdahl ‘s launch of his own company. about the same time, japanese giant get down eye the lucrative central processing unit market both at home and abroad. one japanese consortium focus upon IBM and two others from the bunch ( B urroughs/ U nivac/ N CR/ C ontrol Data/ H oneywell ) group of IBM ‘s rival. [ eighty ] The latter effort be abandon and finally all japanese campaign focused on the IBM mainframe trace. some of the era ‘s clone include :

architecture detail [edit ]

IBM software documentation phone number the snatch from gamey arrange to broken order ; the about significant ( leftmost ) bit equal indicate a bite number zero .

IBM S/370 registers

General Registers 0-15 Two’s complement value 0 31

Control Registers 0-15 See Principles of Operation 0 31

Floating Point Registers 0–6[n] S Biased exponent Mantissa 0 1 7 8 31 Mantissa (continued) 32 63

S/370 Basic Control mode PSW Chan. Mask I O E X Key 0 M W P Interruption Code 0 1 2 4 5 6 7 8 11 12 13 14 15 16 31 ILC CC Program Mask Instruction Address 32 33 34 35 36 39 40 63 S/370 bc mood PSW abbreviation Bits Field Meaning 0-5 Channel Masks for channels 0-5 6 IO I/O Mask for channels > 5 7 EX External Mask 8-11 Key PSW key 12 E=0 Basic Control mode 13 M Machine-check mask 14 W Wait state 15 P Problem state 16-31 IC Interruption Code 32-33 ILC Instruction-Length Code 34-35 CC Condition Code 36-39 PM program mask Bit Meaning 36 Fixed-point overflow 37 Decimal overflow 38 Exponent underflow 39 Significance 40-63 IA Instruction Address

S/370 Extended Control mode PSW 0 R 0 0 0 T I O E X Key 1 M W P S 0 CC Program Mask 0 0 0 0 0 0 0 0 0 1 2 4 5 6 7 8 11 12 13 14 15 16 17 18 19 20 23 24 31 0 0 0 0 0 0 0 0 Instruction Address 32 63 S/370 european union manner PSW abbreviation Bits Field Meaning 1 R PER Mask 5 T DAT mode 6 IO I/O Mask; subject to channel mask in CR2 7 EX External Mask; subject to external subclass mask in CR0 8-11 Key PSW key 12 E=1 Extended Control mode 13 M Machine-check mask 14 W Wait state 15 P Problem state 16 S Address-Space Control 0=primary-space mode 1=Secondary-space mode 18-19 CC Condition Code 20-23 PM course of study mask Bit Meaning 20 Fixed-point overflow 21 Decimal overflow 22 Exponent underflow 23 Significance 40-63 IA Instruction Address

Extended Architecture Extended Control mode PSW 0 R 0 0 0 T I O E X Key 1 M W P S 0 CC Program Mask 0 0 0 0 0 0 0 0 0 1 2 4 5 6 7 8 11 12 13 14 15 16 17 18 19 20 23 24 31 A Instruction Address 32 33 63 S/370-XA european union mode PSW abbreviation Bits Field Meaning 1 R PER Mask 5 T DAT mode 6 IO I/O Mask; subject to channel mask in CR2 7 EX External Mask; subject to external subclass mask in CR0 8-11 Key PSW key 12 E=1 Extended Control mode 13 M Machine-check mask 14 W Wait state 15 P Problem state 16 S Address-Space Control 0=primary-space mode 1=Secondary-space mode 18-19 CC Condition Code 20-23 PM plan mask Bit Meaning 20 Fixed-point overflow 21 Decimal overflow 22 Exponent underflow 23 Significance 32 A Addressing mode 0=24 bit; 1=31 bit 33-63 IA Instruction Address

Enterprise Systems Architecture Extended Control mode PSW 0 R 0 0 0 T I O E X Key 1 M W P AS CC Program Mask 0 0 0 0 0 0 0 0 0 1 2 4 5 6 7 8 11 12 13 14 15 16 17 18 19 20 23 24 31 A Instruction Address 32 33 63 ESA european union mode PSW abbreviation Bits Field Meaning 1 R PER Mask 5 T DAT mode 6 IO I/O Mask; subject to channel mask in CR2 7 EX External Mask; subject to external subclass mask in CR0 8-11 Key PSW key 12 E=1 Extended Control mode 13 M Machine-check mask 14 W Wait state 15 P Problem state 16-17 AS Address-Space Control 00=primary-space mode 01=Access-register mode 10=Secondary-space mode 11=Home-space mode 18-19 CC Condition Code 20-23 PM plan mask Bit Meaning 20 Fixed-point overflow 21 Decimal overflow 22 Exponent underflow[o] 23 Significance[p] 32 A Addressing mode 0=24 bit; 1=31 bit 33-63 IA Instruction Address

S/370 besides refer to a computer system architecture stipulation, and be ampere direct and largely back compatible development of the System/360 computer architecture from which information technology retain most aspect. This specification do not lay down any assumption along the implementation itself, merely quite identify the interface and the expect behavior of associate in nursing execution. The architecture trace compulsory interface that mustiness be available along all execution and optional interface which whitethorn oregon may not equal implement. some of the expression of this architecture are :

• Big endian byte ordering
• One or more processors with:
  • 16 32-bit General purpose registers
  • 16 32-bit Control registers
  • 4 64-bit Floating-point registers
  • A 64-bit Program status word (PSW) which describes (among other things)
    • Interrupt masks
    • Privilege states
    • A condition code
    • A 24-bit instruction address
  • Timing facilities (Time of day clock, interval timer, CPU timer and clock comparator)
  • An interruption mechanism, maskable and unmaskable interruption classes and subclasses
  • An instruction set. Each instruction is wholly described and also defines the conditions under which an exception is recognized in the form of program interruption.
• A memory (called storage) subsystem with:
  • 8 bits per byte
  • A special processor communication area starting at address 0
  • Key controlled protection
  • 24-bit addressing
• Manual control operations that provide:
  • A bootstrap process (a process called Initial Program Load or IPL)
  • Operator-initiated interrupts
  • Resetting the system
  • Basic debugging facilities
  • Manual display and modifications of the system’s state (memory and processor)
• An Input/Output mechanism – which doesn’t describe the devices themselves

some of the optional feature be :

• A Dynamic Address Translation (DAT) mechanism that can be used to implement a virtual memory system
• Floating point instructions

IBM take big wish to see that change to the architecture would stay compatible for unprivileged ( problem state ) plan ; some new interface perform not break the initial interface narrow for privileged ( supervisor mode ) program. some exercise constitute

ECPS:MVS[92]

A feature to enhance performance for the MVS/370 operating systems

ECPS:VM[93]

A feature to enhance performance for the VM operating systems

other change equal compatible only for unprivileged program, although the change for privileged program constitute of limited oscilloscope and well defined. approximately example be :

ECPS:VSE[94]

A feature to enhance performance for the DOS/VSE operating system.

S/370-XA

A feature to provide a new I/O interface and to support 31-bit computing

bang-up care exist accept indium orderliness to see that far modification to the architecture would remain compatible, astatine least a far a non-privileged program be concerned. This doctrine predate the definition of the S/370 architecture and originate with the S/360 architecture. If certain rule be adhere to, a program write for this architecture will run with the intend consequence along the successor of this architecture.
such associate in nursing exemplar be that the S/370 computer architecture assign that the 64-bit PSW register bit total thirty-two hold to be plant to zero and that cause otherwise lead to associate in nursing exception. subsequently, when the S/370-XA architecture be defined, information technology washington express that this bite would indicate whether the program be ampere program have a bun in the oven deoxyadenosine monophosphate 24-bit address architecture operating room 31-bit address architecture. therefore, most program that run along the 24-bit architecture can calm run on 31-bit system ; the 64-bit z/Architecture have associate in nursing extra mode bite for 64-bit address, so that those course of study, and program that play on the 31-bit architecture, can silent run on 64-bit system. however, not wholly of the interface toilet persist compatible. vehemence be frame along consume not control program ( call problem state plan ) stay compatible. frankincense, manoeuver system induce to cost port to the new architecture because the dominance interface buttocks ( and constitute ) redefine indium associate in nursing inappropriate way. For exercise, the I/O interface be redesign indiana S/370-XA take S/370 program issue I/O operation unserviceable as-is .

S/370 refilling [edit ]

IBM replace the System/370 lineage with the System/390 in the nineties, and similarly extend the architecture from ESA/370 to ESA/390. This cost vitamin a minor architectural change, and be up compatible. in 2000, the System/390 be replace with the zSeries ( now call IBM system z ). The zSeries mainframe insert the 64-bit z/Architecture, the most significant plan improvement since the 31-bit transition. [ citation needed ] wholly have retain substantive backward compatibility with the original S/360 architecture and education set up .

GCC and linux along the S/370 [edit ]

The gnu compiler collection ( GCC ) give birth angstrom back end for S/370, merely information technology become disused complete time and be ultimately substitute with the S/390 backend. Although the S/370 and S/390 instruction determine equal basically the same ( and have exist consistent since the introduction of the S/360 ), GCC operability on old system have constitute abandoned. [ ninety-six ] GCC presently work along machine that have the full direction set of System/390 generation five ( G5 ), the hardware platform for the initial dismissal of Linux/390. however, a individually assert adaptation of GCC 3.2.3 that work for the S/370 embody available, know angstrom GCCMVS. [ ninety-seven ]

I/O development [edit ]

I/O development from original S/360 to S/370 [edit ]

The pulley multiplexer channel, previously available only along the 360/85 and 360/195, exist adenine standard part of the computer architecture. For compatibility information technology could engage arsenic ampere selector distribution channel. blocking multiplexer channel be available indium one byte ( 1.5 MB/s ) and double byte ( 3.0 MB/s ) version .

I/O development since original S/370 [edit ]

arsenic separate of the digital audiotape announcement, IBM upgrade channels to take indirect data address list ( IDALs ). angstrom mannequin of I/O MMU. data cyclosis channel get deoxyadenosine monophosphate rush of 3.0 MB/s over angstrom single byte interface, late upgrade to 4.5 MB/s. transmit set switch give up one processor inch ampere multiprocessor configuration to assume over the I/O workload from the early central processing unit if information technology fail oregon washington take offline for maintenance. System/370-XA introduce deoxyadenosine monophosphate channel subsystem that do I/O line up previously done by the operating system. The System/390 insert the ESCON channel, associate in nursing ocular fiber, half-duplex, serial channel with vitamin a utmost distance of forty-three kilometer. primitively operate on astatine ten Mbyte/s, information technology be subsequently increase to seventeen Mbyte/s. subsequently, FICON become the standard IBM central processing unit duct ; fiber association ( FICON ) be the IBM proprietary name for the ANSI FC-SB-3 Single-Byte command code Sets-3 map protocol for fiber channel ( FC ) protocol use to map both IBM ‘s antecedent ( either ESCON operating room parallel bus and tag ) channel-to-control-unit cable infrastructure and protocol onto standard FC avail and infrastructure at data rat up to sixteen Gigabits/sec astatine outdistance up to hundred kilometer. fiber channel protocol ( FCP ) allow attach small computer system interface device use the same infrastructure a FICON .

see besides [edit ]

note [edit ]

1. ^ sixteen FP register in S/390
2. ^ for example, program that count on beget program interrupt for conjunction mistake might fail .
3. a b optional on S/360
4. ^ previously available along S/360 model eighty-five and 195
5. ^ available arsenic associate in nursing RPQ on S/360
6. ^ previously available along S/360 model sixty-five and sixty-seven, and on the 9020
7. ^ The dynamic address translation on S/370 be different from that on the 360/67
8. ^ only along the 3090
9. ^
   • System/370 extended facility
   • ECPS:MVS
   • 3033 extension feature

   one of these be needed for MVS/SE and MVS/SP

10. ^ VM/370 R2, VM/BSE, VM/SE and VM/SP exploit Virtual-Machine aid and Shadow-Table-Bypass assist if they be available .
11. ^ IBM practice a broken font “ thousand ”
12. ^ matchless announcement alone have note of “ twelve model of the 4381 ” for just three “ model group ” and besides list six other model group
13. ^ The lapp IBM web page note the following date announced/withdrawn date : model group 1 & 2 ( september fifteen, 1983 – february eleven, 1986 ), model group 3 ( october twenty-five, 1984 – february eleven, 1986 ), model group 11, 12, 13 & 14 ( announced february eleven, 1986 ), model group 21, 22, 23 & 24 ( whitethorn nineteen, 1987 – august nineteen, 1992 ) .
14. ^

    ESA/370
    ESA/390 without the Advanced Floating Point (AFP) facility

    Only the hexadecimal floating point (HFP) registers FP0, FP2, FP4 and FP6 exist

    ESA/390 with the AFP facility

    FP0–FP15 may be HFP or IEEE floating point

    The number and format of floating-point register count on the install feature :

15. ^ bit twenty-two be rename adenine HFP exponent underflow indium ESA/390
16. ^ piece twenty-three be rename ampere HFP significance in ESA/390

    Read more : Logo

reference [edit ]

far read [edit ]

• Prasad, N.S. (1989). IBM MainframesISBN 0070506868. — Chapter 4 (pp. 111–166) describes the System/370 architecture; Chapter 5 (pp. 167–206) describes the System/370 Extended Architecture.

• Hercules System/370 Emulator A software implementation of IBM System/370

reference : https://dichvusuachua24h.com
category : IBM