Area Code. See Device Code.
Assembler Language. A programming language that is more closely related to actual machine language than either RPG or FORTRAN.
Baud. A communications term that specifies bits per second. For example, 600 baud is the same as 600 bits per second.
Binary Synchronous Communication (BSC). A mode (of the synchronous communications adapter) that provides for point-to-point or multipoint operation.
BSC. See Binary Synchronous Communications.
Byte. An increment of information that is made up of eight bit positions (0 1 2 3 4 5 6 7). Each 1130 word location (in core storage) is made up of two bytes.
Central Processing Unit (CPU). The central machine unit (the 1131) in the 1130 System. Core storage is housed in the CPU. The logical circuitry that causes execution of program instructions is also in the CPU.
Core Storage. Core storage (also called storage) contains programs being executed and input data to be processed. Processed data is set up (by the program) in output areas and then moved to one or more output devices.
CPU See Central Processing Unit.
Cycle-Steal. The method of data transfer between certain I/O devices and main storage. The I/O device "steals" a CPU cycle, when necessary, to transfer a word to or from main storage. The CPU program is slowed only to the extent of the amount of cycles "stolen."
Device Address. See Device Code.
Device Code. The binary field in input/output control commands that specifies the I/O device involved in the operation. (Also called area code or device address.)
Device Status Word(DSW). A 16-bit increment of information that specifies the status or condition of an I/O device. Each I/O device has one or more associated DSW's.
Direct Address. A method of forming the effective address from values in an instruction or from values in an instruction in a register.
Direct Program Control. Refers to the need for program control for each operation performed. Specifically, some I/O devices require instruction and input/output control command execution for each data character transferred to or from main storage. Contrast with cycle steal.
Displacement. A field in short-format instructions that is usually added to the contents of a register to obtain the effective address. The displacement has other uses in certain instructions.
Double Precision Format. A binary number format of 32 bits (two words). The arithmetic sign is the leftmost bit. See sign bit.
DSW. See Device Status Word.
Effective Address (EA). The actual address of data or an instruction in main storage. The effective address is derived in various ways, depending upon the instruction and the manner in which that instruction is executed.
FORTRAN. FORTRAN (FORmula TRANslation) is a high-level programming language designed specifically for engineering and scientific data-processing applications.
Four-Wire Operation. A communications arrangement of terminals that use two data paths. The paths are arranged so that signals can be transmitted on one path only and received on the other path. Four physical wires may or may not make up the data paths.
Half-Duplex. A communications method of operation in which each terminal can transmit or receive information signals, but only one of these (transmit or receive) at a time.
ILSW. See Interrupt Level Status Word.
Indirect Address. In indirect addressing, the effective address is the contents of a core-storage location which itself is located by direct addressing.
Input/Output Control Command (IOCC). A 32-bit increment of information that specifies the operation, data address, I/O device, etc. during I/O device operations. An IOCC is to an I/O device what an instruction is to the CPU.
Interrupt. The temporary stopping of an operation in order to perform some higher priority operation. Interrupts are used to transfer data to or from I/O devices, handle unusual I/O device conditions, and terminate I/O device operations.
Interrupt Level Status Word (ILSW). A 16-bit increment of information that specifies the I/O device(s) causing an interruption. There are six levels of interruption (0 through 5) but only five ILSW's (for levels 1 through 5).
Interrupt Vector. There are six interrupt-vector locations in main storage. These locations point to the beginning of the interrupt-handling subroutine for the associated interrupt level. (The interrupt vectors must be program-loaded with the desired addresses at program-loading time.)
IOCC. See Input/Output Control Command.
Multipoint. A private line arrangement in which more than two communication terminals are capable of communication among themselves but on the same line.
Point-to-Point. The transmission of data directly from one terminal to another without the use of any intermediate computer or terminal.
RPG. RPG (Report Program Generator) is a high-level programming language that is mainly applicable to commercial data-processing applications.
SAC. See Storage Access Channel.
SCA. See Synchronous Communications Adapter.
Sign Bit. The leftmost bit of a single- or double-precision binary operand. When this bit is at a value of zero, the binary operand is positive; when this bit is at a value of 1, the binary operand is negative.
Single Precision Format. A binary number format of 16 bits (one word). The sign is specified by the leftmost (high-order) bit. See Sign Bit.
Storage. See Core Storage.
Storage Access Channel (SAC). This channel provides for attaching certain I/O devices to the 1130 system.
STR. See Synchronous Transmit-Receive.
Synchronous Communications Adapter (SCA). A feature in the 1130 that enables the system to function in a communications network in either point-to-point or multipoint operation. The term "synchronous" signifies that signal transmission is continuous rather than start-stop for each character.
Synchronous Transmit-Receive (STR). A mode (of the synchronous communications adapter) that provides for point-to-point operation only.
Two-Wire Operation. A communications operation of terminals that can transmit in either direction (from terminal A to terminal B or from terminal B to terminal A) but not both at the same time.
Word. The amount (16 bits) of bit positions available for data at each core-storage location. The positions of a word are numbered 0 to 15, left to right.
Wraparound. Going sequentially from the highest core-storage location to core-storage location 0000.

But wait, there's MORE...

Valid HTML 4.01 Transitional