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39-564: The MicroVAX I , code-named Seahorse , introduced in October 1984, was one of DEC's first VAX computers to use very-large-scale integration (VLSI) technology. The KA610 CPU module (also known as the KD32 ) contained two custom chips which implemented the ALU and FPU while TTL chips were used for everything else. Two variants of the floating point chips were supported, with the chips differing by

78-752: A single-board MicroVAX II designed for automatic test equipment and manufacturing applications which only ran DEC's real-time VAXELN operating system. A KA620 with 1 MB of memory bundled with the VAXELN Run-Time Package 2.3 was priced at US$ 5,000. Mira referred to a fault-tolerant configuration of the MicroVAX II developed by DEC's European Centre for Special Systems located in Annecy in France. The system consisted of two MicroVAX 78032 microprocessors, an active and standby microprocessor in

117-516: A "production-quantity optical drive ", the Optimem 1000, offering 1 GB of storage on 12-inch disks using a laser-based recording technology, taking advantage of a substantially increased track density compared to contemporary magnetic recording technologies. The process of recording involved focusing the laser beam on the metal layer of the disk, this causing a "decomposable polymer" layer underneath to generate "gaseous components" and to push up on

156-574: A 16.67 MHz (60 ns cycle time) CVAX chip set. They supported up to 64 MB of memory. Very-large-scale integration Very-large-scale integration ( VLSI ) is the process of creating an integrated circuit (IC) by combining millions or billions of MOS transistors onto a single chip. VLSI began in the 1970s when MOS integrated circuit (metal oxide semiconductor) chips were developed and then widely adopted, enabling complex semiconductor and telecommunications technologies. The microprocessor and memory chips are VLSI devices. Before

195-515: A few years at Memorex , Alan Shugart decided to strike out on his own in 1973. After gathering venture capital , he started Shugart Associates. The original business plan was to build a small-business system (similar to the IBM 3740 ) dealing with the development of various major components, including floppy disk drives and printers. After two years, Shugart had exhausted his startup money and had no product to show for it. The board then wanted to focus on

234-509: A floppy disk drive, the SA1000 form factor compatible with the 8-inch floppy drive form factor. Founded in 1973, Shugart Associates was purchased in 1977 by Xerox , which then exited the business in 1985 and 1986, selling the brand name and the 8-inch floppy product line (in March 1986) to Narlinger Group, which ultimately ceased operations circa 1991. After a distinguished career at IBM and

273-557: A single box, connected by Ethernet and controlled by a software switch. When a fault was detected in the active microprocessor, the workload was switched over to the standby microprocessor. A MicroVAX II in BA213 enclosure. BA23- or BA123-enclosure MicroVAX upgraded with KA650 CPU module containing a CVAX chip set. BA23- or BA123-enclosure MicroVAX upgraded with KA655 CPU module. BA23- or BA123-enclosure MicroVAX upgraded with KA660 CPU module. The MicroVAX 2000 , code-named TeamMate ,

312-460: A single chip (later hundreds of thousands, then millions, and now billions). The first semiconductor chips held two transistors each. Subsequent advances added more transistors, and as a consequence, more individual functions or systems were integrated over time. The first integrated circuits held only a few devices, perhaps as many as ten diodes , transistors , resistors and capacitors , making it possible to fabricate one or more logic gates on

351-477: A single device. Now known retrospectively as small-scale integration (SSI), improvements in technique led to devices with hundreds of logic gates, known as medium-scale integration (MSI). Further improvements led to large-scale integration (LSI), i.e. systems with at least a thousand logic gates. Current technology has moved far past this mark and today's microprocessors have many millions of gates and billions of individual transistors. At one time, there

390-680: The KA650 CPU module. The MicroVAX 3300 and MicroVAX 3400, code-named Mayfair II , were entry-level to mid-range server computers introduced on 19 October 1988 intended to compete with the IBM AS/400 . They used the KA640 CPU module. The MicroVAX 3800 and MicroVAX 3900 , code-named Mayfair III , were introduced in April 1989. They were high-end models in the MicroVAX family, replacing

429-420: The 1950s saw the possibilities of constructing far more advanced circuits. However, as the complexity of circuits grew, problems arose. One problem was the size of the circuit. A complex circuit like a computer was dependent on speed. If the components were large, the wires interconnecting them must be long. The electric signals took time to go through the circuit, thus slowing the computer. The invention of

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468-471: The MicroVAX 3500 and MicroVAX 3600, and were intended to compete with the IBM AS/400 . At introduction, the starting price of the MicroVAX 3800 was US$ 81,000 and that of the MicroVAX 3900 was US$ 120,200. A variant of the MicroVAX 3800, the rtVAX 3800, was intended for real-time computing (RTC) applications such as computer-aided manufacturing (CAM). These systems used the KA655 CPU module, which contained

507-428: The design plane, and look ahead to post-silicon: Shugart Associates Shugart Associates (later Shugart Corporation ) was a computer peripheral manufacturer that dominated the floppy disk drive market in the late 1970s and is famous for introducing the 5 + 1 ⁄ 4 -inch "Minifloppy" floppy disk drive. In 1979 it was one of the first companies to introduce a hard disk drive form factor compatible with

546-459: The earliest hard drives compatible with a floppy drive form factor . By 1983, Shugart Associates had shipped over 100,000 such drives. In the early 1980s, in order to avoid development and start-up costs, the company turned to Matsushita Communications Inc., a subsidiary of Panasonic Corporation (then known as Matsushita Electric Industrial Co., Ltd), for its half-height 5 + 1 ⁄ 4 -inch drives, sending that company on its way to becoming

585-400: The early 1960s, and then medium-scale integration (MSI) in the late 1960s. General Microelectronics introduced the first commercial MOS integrated circuit in 1964. In the early 1970s, MOS integrated circuit technology allowed the integration of more than 10,000 transistors in a single chip. This paved the way for VLSI in the 1970s and 1980s, with tens of thousands of MOS transistors on

624-675: The early 1980s, but lost its popularity later because of the advent of placement and routing tools wasting a lot of area by routing , which is tolerated because of the progress of Moore's law . When introducing the hardware description language KARL in the mid-1970s, Reiner Hartenstein coined the term "structured VLSI design" (originally as "structured LSI design"), echoing Edsger Dijkstra 's structured programming approach by procedure nesting to avoid chaotic spaghetti-structured programs. As microprocessors become more complex due to technology scaling , microprocessor designers have encountered several challenges which force them to think beyond

663-462: The engineers who worked on SASI left in 1981 to found host adapter maker Adaptec . Also in 1979, Shugart Associates introduced the SA-1000, a series of hard disk drives that kept as many mechanical, electrical and formatting similarities as possible with its floppy-drive counterparts. Their physical dimensions, including mounting holes, were the same as an 8-inch floppy drive, making them some of

702-407: The floppy disk drive, but Shugart wished to continue the original plan. Official company documents state that Shugart quit, but he himself claims that he was fired by the venture capitalists. Shugart went on with Finis Conner to found Shugart Technology in 1979, which was later renamed to Seagate Technology in response to a legal challenge by Xerox. The 5 + 1 ⁄ 4 -inch floppy disk drive

741-549: The higher end complement of the MicroVAX family. These new machines featured more than three times the performance of the MicroVAX II and supported 32 MB of ECC main memory (twice that of the MicroVAX II). The performance improvements over the MicroVAX II resulted from the increased clock rate of the CVAX chip set, which operated at 11.11 MHz (90 ns cycle time) along with a two-level, write-through caching architecture. It used

780-528: The highest efficiency. Structured VLSI design is a modular methodology originated by Carver Mead and Lynn Conway for saving microchip area by minimizing the interconnect fabric area. This is obtained by repetitive arrangement of rectangular macro blocks which can be interconnected using wiring by abutment . An example is partitioning the layout of an adder into a row of equal bit slices cells. In complex designs this structuring may be achieved by hierarchical nesting. Structured VLSI design had been popular in

819-401: The integrated circuit by Jack Kilby and Robert Noyce solved this problem by making all the components and the chip out of the same block (monolith) of semiconductor material. The circuits could be made smaller, and the manufacturing process could be automated. This led to the idea of integrating all components on a single-crystal silicon wafer, which led to small-scale integration (SSI) in

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858-470: The introduction of VLSI technology, most ICs had a limited set of functions they could perform. An electronic circuit might consist of a CPU , ROM , RAM and other glue logic . VLSI enables IC designers to add all of these into one chip . The history of the transistor dates to the 1920s when several inventors attempted devices that were intended to control current in solid-state diodes and convert them into triodes. Success came after World War II, when

897-659: The lack of Q-Bus or any expansion bus. The system could have a Shugart -based harddrive with ST412 interface and MFM encoding and had a built in 5.25-inch floppy drive (named RX33 in DEC jargon) for software distribution and backup. Supported operating systems were VMS and ULTRIX. It was packaged in a desktop form factor. The MicroVAX 3100 Series was introduced in 1987. These systems were all packaged in desktop enclosures. The MicroVAX 3500 and MicroVAX 3600, code-named Mayfair , were introduced in September 1987 and were meant to be

936-537: The largest floppy drive manufacturer in the world. In 1985, in order to resolve an inventory accumulation and as part of its exit strategy, Xerox gave up Shugart's exclusive rights to the Matsushita half-height 5 + 1 ⁄ 4 -inch floppy drives. Shugart's eventual downfall came about partially as a result of the company failing to develop a reliable 80-track disk drive. In 1983 the company changed its name to Shugart Corporation. In late 1983, Shugart announced

975-634: The means by which more memory was added to the system. The MicroVAX II supported 1 to 16 MB of memory through zero, one or two memory expansion modules. The MS630 memory expansion module was used for expanding memory capacity. Four variants of the MS630 existed: the 1 MB MS630-AA , 2 MB MS630-BA , 4 MB MS630-BB and the 8MB MS630-CA . The MS630-AA was a dual-height module, whereas the MS630-BA, MS630-BB and MS630-CA were quad-height modules. These modules used 256 Kb DRAMs and were protected by byte-parity, with

1014-403: The metal layer, forming a bubble. This deformation would cause a change in the intensity of the reflected light from a laser reading the disk, thus providing a means of data storage. Initial OEM pricing for the drive was given as $ 6,000 per unit in 250-unit quantities with disks priced about $ 266 each (UK price). Disks with capacities of up to 3 GB were reportedly being developed. Optimem

1053-455: The module implemented the external interface for the microprocessor, Q22-bus interface and the scatter-gather map for DMA transfers over the Q22-Bus. The module also contained 1 MB of memory, an interval timer, two ROMs for the boot and diagnostic facility, a DZ console serial line unit and a time-of-year clock. A 50-pin connector for a ribbon cable near the top left corner of the module provided

1092-533: The parity logic located on the module. The modules connected to the CPU module via the backplane through the C and D rows and a 50-conductor ribbon cable. The backplane served as the address bus and the ribbon cable as the data bus. The MicroVAX II came in three models of enclosure: The Robotron K 1820 is a copy of the MicroVAX II developed in the GDR and was produced for a short period of time in 1990. KA620 referred to

1131-451: The then-current generation of 65 nm processors. Current designs, unlike the earliest devices, use extensive design automation and automated logic synthesis to lay out the transistors, enabling higher levels of complexity in the resulting logic functionality. Certain high-performance logic blocks, like the SRAM ( static random-access memory ) cell, are still designed by hand to ensure

1170-413: The type of floating point instructions supported, F and G, or F and D. The system was implemented on two quad-height Q-bus cards - a Data Path Module (DAP) and Memory Controller (MCT). The MicroVAX I used Q-bus memory cards, which limited the maximum memory to 4MiB. The performance of the MicroVAX I was rated at 0.3 VUPs , equivalent to the earlier VAX-11/730 . The MicroVAX II , code-named Mayflower ,

1209-403: The use of silicon and germanium crystals as radar detectors led to improvements in fabrication and theory. Scientists who had worked on radar returned to solid-state device development. With the invention of the first transistor at Bell Labs in 1947, the field of electronics shifted from vacuum tubes to solid-state devices . With the small transistor at their hands, electrical engineers of

MicroVAX - Misplaced Pages Continue

1248-457: Was a low-cost MicroVAX introduced on 10 February 1987. In January 1987, the MicroVAX 2000 was the first VAX system targeted at both universities and VAX programmers who wanted to work from remote locations. The MicroVAX 2000 used the same microprocessor and floating-point coprocessor as the MicroVAX II, but was feature reduced in order to lower the cost. Limitations were a reduced maximum memory capacity, 14 MB versus 16 MB in MicroVAX II systems and

1287-597: Was a mid-range MicroVAX introduced in May 1985 and shipped shortly thereafter. It ran VAX/VMS or, alternatively, ULTRIX , the DEC native Unix operating system. At least one non-DEC commercial operating system was available, BSD Unix from mt Xinu . It used the KA630-AA CPU module, a quad-height Q22-Bus module, which featured a MicroVAX 78032 microprocessor and a MicroVAX 78132 floating-point coprocessor operating at 5 MHz (200 ns cycle time). Two gate arrays on

1326-501: Was an effort to name and calibrate various levels of large-scale integration above VLSI. Terms like ultra-large-scale integration (ULSI) were used. But the huge number of gates and transistors available on common devices has rendered such fine distinctions moot. Terms suggesting greater than VLSI levels of integration are no longer in widespread use. In 2008, billion-transistor processors became commercially available. This became more commonplace as semiconductor fabrication advanced from

1365-531: Was announced in December 1977 at $ 450. In 1979, Shugart Associates introduced the "Shugart Associates System Interface" (SASI) to the computing world; the interface subsequently evolved into SCSI (Small Computer System Interface). The first standard process completed in 1986 with ANSI standard X3.131-1986 (popularly known as SCSI-1 ) as the result. Larry Boucher led the SASI engineering team; he and several of

1404-551: Was introduced by Shugart in September 1976 as the Shugart SA-400 Minifloppy (Shugart's trademarked brand name ) at an OEM price of $ 390 for the drive and $ 45 for ten diskettes. The SA-400 and related models became the company's best selling products, with shipments of up to 4000 drives per day. The original SA-400 was single-sided with 35-tracks and used FM (single density) recording. It could be used on either hard - or soft-sector floppy controllers and

1443-459: Was sold in March 1986 to Narlinger, which promptly rebranded itself as Shugart Corporation Under the management of Narlinger, Shugart acquired several discontinued product lines such as Tandon's 8-inch floppy drives in 1986 and in 1988 bought the Optotech 5984 Write Once Read Many (WORM) drive and its manufacturing facility for less than US$ 4-million. In 1987, it acquired Kennedy Company ,

1482-414: Was sold to Cipher Data in 1986 who then discontinued operations in 1991. Shugart's operating losses in 1984 along with Xerox's own troubles led Xerox to conclude in 1985 that Shugart businesses were no longer strategically important, resulting in a decision to close down Shugart rather than invest in recovery. Most of Shugart's businesses were shut down afterwards; however its floppy disk drive business

1521-559: Was specified at 80.6 kB with a soft sectored controller. The drive became the basis of the disk system on the Radio Shack TRS-80 Model I , Apple II , and many other early microcomputers . Xerox announced acquisition of Shugart Associates in August 1977 and completed its purchase that December at a price of about $ 41 million. The 440 kilobyte SA450, a double-sided double-density 5¼-inch full height floppy disk drive

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