Honeywell Level 6

As initially introduced, the Level 6 consisted of three models: the 6/06, the 6/34, and the 6/36. The CPU featured a real-time clock, a ROM bootstrap loader and 64 interrupt levels. The architecture provided a variety of addressing modes and 18 programmer-visible registers. Rack-mount and tabletop versions were available.

These systems supported up to 64 K words (KW) of MOS memory with a cycle time of 650 nanoseconds.

All three models all featured the Megabus, which was a proprietary asynchronous bus architecture.

By 1978, the line had been extended downwards with the introduction of the 6/23 and 6/33, and upwards with the 6/43, 6/47, 6/53, and 6/57. The 6/23 did not support the Megabus. The 6/33 was the new entry-level upgradable model. The other four models supported up to 1 MW (Mega Words) of memory and 26 registers. A memory management unit (MMU), optional on the 6/43 and 6/47, and standard on the 6/53 and 6/57, supported memory segmentation and four protection rings. An optional Scientific Instruction Processor (SIP) added single- and double-precision hardware floating-point instructions. The 6/47 and 6/57 were enhanced versions of the 6/43 and 6/53 respectively which added a Commercial Instruction Processor (CIP) including 30 additional instructions for character-string manipulation and decimal arithmetic.{{cite book|last1=Honeywell, Inc.|title=Honeywell Level 6 Minicomputer Systems Handbook|date=October 1978|url=https://bitsavers.org/pdf/honeywell/small_systems/series60level6/CC71_Level6Hbk_Oct78/|accessdate=July 26, 2014}} Among the final developments in the line were the high-end 32-bit 6/95-1, 6/98-1 and dual processor 6/95-2 and 6/98-2 models.{{cite news|title=Hardware Roundup Large and Medium-Scale Systems|url=https://books.google.com/books?id=botwBgcSATQC&pg=PA70|accessdate=December 20, 2014|work=Computerworld|date=October 6, 1986}}

In the 1980s, Honeywell's Datanet 8{{cite news|title=Honeywell revamps net architecture|url=https://books.google.com/books?id=w3IudMVoEusC&pg=PA1|accessdate=December 20, 2014|work=Computerworld|date=October 7, 1985}} line of communications processors, often used as front-end processors for DPS 8 mainframes, shared many hardware components with DPS 6. Another specialised derivative of the Level 6 was the Honeywell Page Printing System.{{cite journal|title=A Nonimpact Page Printing System|url=http://www.computer.org/csdl/mags/co/1975/09/01649552.pdf|accessdate=December 20, 2014|journal=IEEE Computer Society|date=September 1975}}

In June 1986, following Honeywell Information Systems' merger with Bull, Honeywell Bull introduced the DPS 6 Plus line of symmetric multiprocessing 32-bit systems, models 410 and 420 (code named MRX - Medium Range eXtended) with up to four processors.{{cite news|title=Honeywell Bull's New Computers|url=https://www.nytimes.com/1987/06/10/business/honeywell-bull-s-new-computers.html|accessdate=July 29, 2014|work=The New York Times|date=June 10, 1987}} In 1987 they introduced the uniprocessor models 210 and 220 (code named LRX - Low Range eXtended), announced the HRX (High Range eXtended), and Computerworld reported that there were more than 50,000 DPS 6 systems installed worldwide.{{cite news|last1=Bozman|first1=Jean S.|title=Honeywell Bull to ax U.S. plants, old systems|url=https://books.google.com/books?id=ldk7z4Q-WWYC&pg=PT12|accessdate=July 29, 2014|work=Computerworld|date=Sep 21, 1987}} The HRX was introduced as the DPS 6000 600 series. Recognising the commercial success of Unix, in 1988 Honeywell Bull introduced an 80386-based Unix co-processor for the DPS 6 Plus 400 series.

The operating system for the Level 6 was GCOS 6:

• GCOS 6 Mod 200 was an entry version of the system oriented toward interactive data entry.
• GCOS 6 Mod 400 was a batch operating system also used to run process-control applications.
• GCOS 6 Mod 600 was a time-sharing operating system.{{cite web|title=Honeywell GCOS 6 |url=http://www.feb-patrimoine.com/projet/gcos6/gcos6.htm |website=FEB-patrimoine |accessdate=July 29, 2014 |url-status=dead |archiveurl=https://web.archive.org/web/20140627131435/http://www.feb-patrimoine.com/projet/gcos6/gcos6.htm |archivedate=June 27, 2014 }}
• The DPS 6 Plus line ran HVS 6 Plus.{{cite news |title=HONEYWELL BULL BRINGS VIRTUAL MULTIPROCESSOR DPS 6s TO EUROPE |url=https://techmonitor.ai/technology/honeywell_bull_brings_virtual_multiprocessor_dps_6s_to_europe |access-date=October 27, 2023 |agency=Tech Monitor |date=June 3, 1987}}{{cite book |title=Communications SNA6 Systems Network Architecture |date=January 1987 |publisher=Honeywell |url=http://bitsavers.trailing-edge.com/pdf/honeywell/small_systems/series60level6/gcos6/GZ68-02_SNA6_Systems_Network_Architecture_198701.pdf | series=Software Release Bulletin | access-date=October 26, 2023}}
• The Pick operating system was a multi-user, time sharing business operating system for the Level 6 platform.{{cite book |title=The Pick System User Reference Manual |date=1985 |page=16 |url=http://bitsavers.trailing-edge.com/pdf/pickSystems/The_Pick_System_Users_Reference_Manual_1985.pdf |access-date=October 27, 2023}}

• General Comprehensive Operating System

{{Reflist}}

• [http://bitsavers.trailing-edge.com/pdf/honeywell/series60level6/ Level 6 documentation at Bitsavers]

{{Honeywell}}

Category:Minicomputers

Category:Honeywell computers

Category:16-bit computers

Category:32-bit computers