Pick operating system
The Pick operating system (often called just "the Pick system" or simply "Pick") is a demand-paged multiuser virtual memory timesharing operating system based around a unique "multivalued" database. It was used primarily for business data processing on a variety of minicomputers, especially in the 1970s and 1980s, although the system and various implementations eventually spread to a large variety of microcomputers and mainframe computers as well, and is still in use today (2004), often on legacy systems. Pick was considered by many who used it to be years ahead of its competitors due to its highly functional database.
Pick was originally implemented as the Generalized Information Retrieval Language System (GIRLS) on an IBM System/360 in 1965 by Don Nelson and Richard (Dick) Pick at TRW for use by the U.S. Army to control the inventory of helicopter parts.
Pick was subsequently commercially released in 1973 by Microdata (and their British distributor CMC) as the Reality Operating System. All data were stored as variable-length text fields (called "attributes") in records (called "items"). Special character delimiters allowed records to contain any number of attributes, and attributes to contain any number of sub-attributes ("multivalues") and "sub-multivalues" of arbitrary length, although records were limited to 32K bytes total. All record retrieval was done by hashing the first field ("attribute zero", also known as the "item identifier", which was limited to 50 characters). All files started as a contiguous group of disk pages, and grew by linking additional "overflow" pages from unused disk space. There were no index structures or sequential files. Files included a "dictionary" fork, and the items in the dictionary fork served as definitions for the names and structure of the items in the data fork.
On the Microdata implementation, a BASIC-like language called Data/BASIC with numerous syntax extensions for database operations was the primary programming language for applications. A system call PROC for executing command files was also provided. A SQL-style language called ENGLISH allowed database retrieval and reporting, but not updates. ENGLISH did not fully allow manipulation of the 3-dimensional multivalued structure of data records, nor did it allow common relational capabilities such as joins (although the data dictionary definition for a field could allow the execution of an arbitrarily calculated lookup in another file). The system included a spooler. A simple text editor for file-system records was provided, but the editor was only suitable for system maintenance, and could not lock records, so most applications were written with the BASIC compiler so as to ensure data validation and allow record locking.
Dick Pick eventually founded Pick & Associates, later renamed Pick Systems, and licensed what was now called "Pick" to a large variety of manufacturers and vendors. Unfortunately, Pick Systems was often tangled in licensing litigation, and relatively little effort was devoted to marketing and improving the software. Subsequent ports of Pick to other platforms generally offered the same tools and capabilities for many years, usually with relatively minor improvements and simply renamed (for example, Data/BASIC became Pick/BASIC and ENGLISH became ACCESS). Licensees often developed proprietary variations and enhancements (for example, Microdata created their own input processor called ScreenPro). The resulting fragmented plethora of non-standard implementations caused the various Pick systems to wander ineffectively while the rest of the industry moved forward. As a result, Pick is no longer as popular or successful or discussed as it once was.
What most characterized Pick was the design and features of the database and the associated retrieval language, which inspired the implementation of similar systems on other platforms. For example, Devcom, a Microdata reseller, wrote a Pick-style database system in FORTRAN in 1979 called Prime INFORMATION, which was eventually sold to Prime Computer, which later sold the technology to Vmark Software. (Microdata itself was eventually bought by McDonnell-Douglas Information Systems.) In 1984 Cosmos released a Pick-style database called Revelation for DOS on the IBM PC. Pick-like systems later became available as database/programming/emulation environments running under Unix and Windows.
The Pick OS invites comparison with MUMPS. Similarities include:
- Both systems are built on the efficient implementation of large, sparse, string-indexed arrays;
- Both commingle the language and the OS;
- Both have a similar domain of applicability.
The Temenos Banking System Globus was originally built on Pick.
Dick Pick died in October 1994. Pick Systems is now called
