- General PUR-float. Before the S/360 were optimized computers either for commercial or for scientific-technical purposes.
- 8-bit character size. Contrary tocontemporary architectures, which with 6-Bit units worked became bytes 8 bits used.
- 32- or 64-Bit of floating decimal point words with hexadecimal basis.
- Sign at integer values is 1 bit
- decimal numbers (packed storage) can variable lengths from 1 to 31 places have. In some“High-level languages” like for example RPG (programming language) only 15 places. Each number occupied thereby a half byte (coded 4 bits , binary decimal numbers), the sign occupies the last 4 bits in the last byte: “C” (1100) and “F” (1111) were the positiveSign, “D” (1101) the minus sign. All other combinations were invalid signs. One must determine the position of the comma due to the operands when programming.
- Variable long character strings have a length field and not with a special character are locked.
- EBCDIC instead of ASCIICode because of the simpler conversion from card code.
- Renouncement of a stack. This makes Linkage conventions necessary, since with subroutine references the status must become secured.
- In principle addressing indicated using a base register. Programs are so in principle independent ofphysical addresses.
- Binary addressing
- all registers are universal registers, which can be used both and accumulators and for the addressing (exception register 0). Advisable however only the registers are starting from No. as base register (addressing). 3 (upto max. 8) to use. Register1 and 2 becomes from certain instructions (e.g. frame. TRT) obligatorily uses. Registers 12 to 15 are used for the call of subroutines and some also still need one for other purposes. A register hands straight around a storage area ofTo address 4096 bytes (4k byte). In the machine instructions stand for a storage address only 2 bytes for order, 4 bits for the register number and 12 bits for the DISPLACEMENT.
- The universal registers are 32 bits long, for addressing become the right24 bits uses, which makes an address area of 16 megabyte possible. With the instructions “BAL” and “BALR” (Branch and left) the return address is stored into a register, in the left 4 bits of the register the condition code is saved. Due to theseIt was not so simply possible for characteristics with the follow-up systems to extend the address area beyond the 16 MT.
The S/360 - Architecture was developed in the course of the last forty years continuously further and culminates at present in architecturethat zSeries.
with the System/360 appeared three operating systems, TOS/360 for installations without non removable disks, DOS/360 for smaller and OS/360 for larger installations with disks. OS/360 is the forerunner of the current z/OS.
A characteristic placedthe system 360/20. Originally pure punch card system was conceived (separation of tabulating machines) and had only a reduced instruction set as (machine instructions). The register width amounted to 16 bits with 8 instead of 16 registers.
the system had the requirementto be all comprehensive. Therefore one selected the number of 360 as reference to the maximum degree of an angle. The requirement could not be fulfilled however, so that afterwards the number was differently defined: 3 one rated as IBM standard and 60for a product developed into the 1960ern. Therefore the successors S/370 and S/390 were called.