IBM System/370 Model 115
| Company type | Computer system |
|---|---|
| Industry | Computer hardware |
| Founded | March 13, 1973 |
| Defunct | March 9, 1981 |
| Products | Mainframe computer |
The IBM System/370 Model 115, introduced on March 13, 1973, represented the entry-level option within IBM's System/370 series. It was designed primarily for customers upgrading from IBM's System/3, 1130 systems, and earlier System/360 Models 20, 22, and 25. Production of the Model 115 ceased on March 9, 1981.
Specifications
This model was equipped with a CPU operating at a 480 nanosecond cycle time. Its primary memory utilized MOSFET monolithic integrated circuit technology, starting at 65,536 bytes (64 KB) and expandable to a maximum of 196,608 bytes (192 KB). The system featured a CRT-based operator console.
Included as standard were the System/370 base and commercial instruction sets with decimal arithmetic capabilities, along with direct disk attachment support for IBM 3340 drives. Optional enhancements included System/370 floating-point instructions, backward compatibility with System/360 Model 20 and IBM 1401, 1440, and 1460 systems, as well as various input/output attachment options.
Input/output
The Model 115 incorporated built-in attachments to facilitate connection with peripheral devices. Its default direct disk interface accommodated two to four IBM 3340 disk drives, allowing storage up to 280 million bytes. Additional integrated attachments available as options included a standard multiplexer channel interface for slower devices or an "integrated card I/O attachment" compatible with either an IBM 5425 Multifunction Card Unit or an IBM 2560 Multifunction Card Machine. The "Integrated Printer Attachment" supported IBM 3203 or IBM 5203 line printer models. A "magnetic tape adapter" provided connectivity for IBM 3210/3211 controllers and tape drives. The "Integrated Communications Adapter" enabled connection of up to four synchronous and eight asynchronous lines or alternatively up to five synchronous lines.
Software
The system ran on either DOS/360 or DOS/VS. DOS/VS offered a single virtual address space of 16,777,216 bytes (16 MB), which could be divided into as many as five partitions. It was capable of executing all System/370 software compatible with its memory and device specifications. Supported programming languages encompassed Assembler, RPG II, COBOL, FORTRAN, and PL/I.