IBM System/370 Model 168
The IBM System/370 Model 168 and Model 158[1] were both announced on August 2, 1972.[2] Prior 370 systems had not "offered virtual storage capability, which was to be a hallmark of the 370 line," and some said that the 168 and 158 were the first "real 370" products.[3] By contrast, "in 1972, the System/370 Advanced Function was released and had new Address Relocation Hardware and now supported four new operating systems (VM/370, DOS/VS, OS/VS1, OS/VS2)."[4] The 158 and 168 were withdrawn on September 15, 1980. FeaturesMain memoryMain memory, which was four-way doubleword interleaved, could be 1 to 8 megabytes, with offerings selectable in increments of one megabyte.[5] The Model 168 used semiconductor memory, rather than the magnetic-core memory used by the 370/165[5] introduced 2 years prior, resulting in a system that was faster and physically smaller than a Model 165.[5]: pp.3–5 System consoleThe newly introduced IBM 3066 Model 2 System console, as with the 165's Model 1
A console printer (up to 85 characters per second) to provide hard copy was optional when the console was in display mode, and required when it was in printer-keyboard mode.[citation needed] Disk storageThe newly introduced Model 11 of IBM's 3330 family of disk drives, featuring removable disk packs, has double the capacity of the prior 100-megabyte offerings.[NB 4][NB 5] It can't be attached to a 370/165.[5]: p.94 MultiprocessingBoth the 370/168 and the 370/158 had MP (multiprocessing) models that offered "tightly coupled multiprocessing.[1] The 168 was described[2] as having "two types of multiprocessing support" since it also offered attaching a second processing unit, an IBM 3062 Attached Processing Unit, which lacked access to Input/Output channels. Extended precision floating-pointThis feature adds support for 128-bit "hexadecimal" floating-point operands. It is standard on all 165 and 168 models, and is an "Optional (no-charge)" feature on the 370/158.[5]: p.137 EmulationThe optional IBM 7070/7074 Compatibility Feature allowed the 168 to "run 7070 and 7074 programs at speeds that, in general, equal or exceed those of the original systems"[6] and yet "not affect normal operation of System/370."[5]: p.139 [6]: p.5 Other listed options are:
There is a limitation, however, described as: System/370 Extended FacilityThis optional facility of the 168-3 provides support for MVS/System Extensions (MVS/SE) and for the later MVS/System Product (MVS/SP).[7] 168-1 & 168-3The Third (June 1975) edition of IBM's 168 Guide introduced the 168-3. IBM referred to the System/370 Model 168-3 as "the company's previous flagship"[8] when comparing it and the then-new IBM 3033. The 168-3 CPU's internal performance has been described as 5–13% faster than the 168-1.[5]: p.125 See alsoNotes
References
|
||||||||||||
Portal di Ensiklopedia Dunia
