IBM Administrative Terminal System
| Company type | Software |
|---|---|
| Industry | Information technology |
| Predecessor | IBM 1440/1460 Administrative Terminal System |
| Founded | 1983 |
| Products | Text and data management software for document processing |
| Owner | IBM |
In 1983, the IBM Administrative Terminal System (ATS/360) was introduced to offer text and data management capabilities tailored for document processing on IBM System/360 platforms.
A predecessor version operated on the IBM 1440 or IBM 1460 Data Processing Systems, while IBM's Service Bureau Corporation provided a specialized iteration named Call/ATS, compatible with IBM 1440 or System/360 DOS environments.
Text and data management
ATS/360 furnished a full suite of tools for document entry, temporary and permanent storage, formatting, printing, archiving, and retrieval functions. It facilitated efficient handling of end-user documents within large enterprises, supporting document revisions and print updates. Additionally, law offices utilized ATS/360 to organize client records such as witness statements and depositions, contributing to several significant legal proceedings.
Device support
At launch, ATS/360 supported only IBM 2741 typewriter terminals; however, through user community efforts, compatibility extended to 2741 terminals featuring the "break feature" as well as IBM 1050 terminals. Support was also provided for the Magnetic Card Selectric Typewriter (MC/ST), which could emulate a 2741 terminal.
The system was specifically engineered to operate with IBM 2311 and IBM 2314 direct access storage units for online "Working" and "Permanent" data storage, along with IBM 2400/3400 tape drives designated for offline backup and printing tasks.
An IBM hardware RPQ upgraded the IBM 1403 Model N1 printer by incorporating a TN print train that mimicked IBM Selectric Courier 72 typeball characters, allowing printed documents to be manually corrected or enhanced.
Another RPQ introduced compatibility with the IBM 3330 direct access storage device, which became popular among ATS/360 users transitioning to early IBM System/370 systems. This modification altered Load Halfword instructions to enable 16-bit disk block addressing compliant with the necessary CCHHR format. It also applied to IBM 3350 drives operating in a 3330-compatible mode—trading some native capacity to emulate two 100 MB drives equivalent to the 3330 within a single unit.
Operating system support
While IBM ceased support after [[OS/VS2 (SVS)|OS/VS/2 Release 1 (SVS)], Peter Haas—previously affiliated with Litton Systems Inc and later Amdahl Corp—extended ATS/360 functionality to MVS environments, including both APs and MPs. This enhancement enabled numerous ATS/360 installations to continue functioning well into the MVS/370 period until the retirement of 2741 terminals and 3705/4705 controllers.
System design
ATS/360 was notably efficient in its use of main memory, often accommodating many terminals within compact partitions or regions. It optimized resource allocation through an internal task dispatcher compatible with PCP, MFT/MFT-II, MVT (its initial targets), SVS, and later MVS via Haas’s modifications.
All input/output processes were managed exclusively using EXCP. Task switching was handled asynchronously through EXCP extensions and synchronously via ATS/360’s Type 1 Supervisor Call instruction (SVC 255). This architecture supported multiple concurrent online (terminal) and offline (peripheral) tasks even under PCP, which normally allowed only a single task. The majority of ATS/360 implementations operated within partitions or regions under MFT/MFT-II or MVT, since offline "format and print" tape operations required dedicated printer partitions; however, tape generation was performed inside ATS/360 itself.
ATS/360 utilized proprietary access methods and file formats. Although offline "format and print" tapes were produced using EXCP, they remained compatible with standard OS utilities employing the BSAM.
ATMS
The system that followed ATS/360, known as ATMS, introduced support for 3270 terminals—functionality not available with ATS/360. Nevertheless, utilizing ATMS necessitated purchasing the CICS data communications software in addition to ATMS itself, leading to a total of three distinct program products. In contrast, ATS/360 was provided without any additional cost.