GCOS
GCOS
(operating system)The GECOS-II operating system was developed by General Electric for the 36-bit GE-635 in 1962-1964. Contrary torumour, GECOS was not cloned from System/360 the GE-635 architecture was very different from the IBM 360and GECOS was more ambitious than DOS/360.
GE Information Service Divsion developed a large specialmulti-computer system that was not publicised because they didnot wish time sharing customers to challenge their bills.Although GE ISD was marketing DTSS - the first commercialtime sharing system - GE Computer Division had no license fromDartmouth and GE-ISD to market it to external customers, sothey designed a time-sharing system to sell as a standard partof GECOS-III, which replaced GECOS-II in 1967. GECOS TSS wasmore general purpose than DTSS, it was more a programmer'stool (program editing, e-mail on a single system) than a BASICTSS.
The GE-645, a modified 635 built by the same people, wasselected by MIT and Bell for the Multics project.Multics' infancy was as painful as any infancy. Bell pulledout in 1969 and later produced Unix.
After the buy-out of GE's computer division by Honeywell,GECOS-III was renamed GCOS-3 (General Comprehensive OperatingSystem). Other OS groups at Honeywell began referring to itas "God's Chosen Operating System", allegedly in reaction tothe GCOS crowd's uninformed and snotty attitude about thesuperiority of their product. GCOS won and this led in the orphaning and eventual death ofHoneywell Multics.
Honeywell also decided to launch a new product line calledLevel64, and later DPS-7. It was decided to mainatin, atleast temporarily, the 36-bit machine as top of the line,because GCOS-3 was so successfull in the 1970s. The plan in1972-1973 was that GCOS-3 and Multics should converge. Thisplan was killed by Honeywell management in 1973 for lack ofresources and the inability of Multics, lacking databasesand transaction processing, to act as a business operatingsystem without a substantial reinvestment.
The name "GCOS" was extended to all Honeywell-marketed productlines and GCOS-64, a completely different 32-bit operatingsystem, significanctly inspired by Multics, was designed inFrance and Boston. GCOS-62, another different 32-bit low-endDOS level was designed in Italy. GCOS-61 represented a newversion of a small system made in France and the new DPS-616-bit minicomputer line got GCOS-6.
When the intended merge between GCOS-3 and Multics failed, thePhoenix designers had in mind a big upgrade of thearchitecture to introduce segmentation and capabilities.GCOS-3 was renamed GCOS-8, well before it started to use thenew features which were introduced in next generationhardware.
The GCOS licenses were sold to the Japanese companies NECand Toshiba who developed the Honeywell products, includingGCOS, much further, surpassing the IBM 3090 and IBM 390.
When Honeywell decided in 1984 to get its top of the rangemachines from NEC, they considered running Multics on them butthe Multics market was considered too small. Due to thedifficulty of porting the ancient Multics code they consideredmodifying the NEC hardware to support the Multics compilers.
GCOS3 featured a good Codasyl database called IDS(Integrated Data Store) that was the model for the moresuccessful IDMS.
Several versions of transaction processing were designed forGCOS-3 and GCOS-8. An early attempt at TP for GCOS-3, nottaken up in Europe, assumed that, as in Unix, a new processshould be started to handle each transaction. IBM customersrequired a more efficient model where multiplexed threadswait for messages and can share resources. Those featureswere implemented as subsystems.
GCOS-3 soon acquired a proper TP monitor called TransactionDriven System (TDS). TDS was essentially a Honeywelldevelopment. It later evolved into TP8 on GCOS-8. TDS andits developments were commercially successful and predated IBMCICS, which had a very similar architecture.
GCOS-6 and GCOS-4 (ex-GCOS-62) were superseded by Motorola 68000-based minicomputers running Unix and the productlines were discontinued.
In the late 1980s Bull took over Honeywell and Bull'smanagement choose Unix, probably with the intent to move outof hardware into middleware. Bull killed the Bostonproposal to port Multics to a platform derived from DPS-6.Very few customers rushed to convert from GCOS to Unix and newmachines (of CMOS technology) are still to be introduced in1997 with GCOS-8. GCOS played a major role in keepingHoneywell a dismal also-ran in the mainframe market.
Some early Unix systems at Bell Labs used GCOS machines forprint spooling and various other services. The field added to"/etc/passwd" to carry GCOS ID information was called the"GECOS field" and survives today as the "pw_gecos" memberused for the user's full name and other human-ID information.