Corvus Systems

Corvus Systems was a technology company founded by Michael D'Addio and Mark Hahn in 1979 and located in San Jose, Silicon Valley, in the U.S. Corvus was a pioneer of the early days of personal computers, producing the first hard disk drives, data backup, and networking devices, commonly for the Apple II platform.

The combination of disk storage, backup, and networking was very popular in primary and secondary education. A classroom would have a single drive and backup with a full classroom of Apple II computers networked together. Students would log in each time they use the computer and access their work.

Corvus went public in 1981 and was traded on the NASDAQ exchange. The company was a modest success in the stock market during its first few years as a public company. The company's founder left Corvus in 1985 as the remaining board of directors made the decision to enter the PC clone market. D'Addio and Hahn went on to found Videonics in 1986.

In 1987 the company filed for Chapter 11. Its demise was partially caused by Ethernet establishing itself over Omninet as the local area network standard for PCs, and partially by the decision to become a PC clone company in a crowded and unprofitable market space.

Innovations

The Corvus is one of many Motorola based personal computers (inexpensive enough for personal use). It was marketed for Government and Business use. Good applications and even internet in a 1982 personal computer with great graphics and a fast processor. In 1982 it was ahead of the IBM PC, in that market, but also more expensive. (absolutely it was not marketed for schools only - that's more like Apple).

The Concept

The Corvus supports making documents with intermixed pictures and text: which was very well presented for a 1982 PC. It also has other application accessed by function keys. Business and pleasure software, mostly practical software applications. (see image link's of Corvus's Desktop - competing computers had only simple text and no desktop arrangement).

The Corvus supported a runtime Pascal interpreter. You can interrupt your programs, edit them, and keep running. Pascal is advanced - not just BASIC. The manuals have all the source code printed just in case you want to read up on your application to change it. Not as innovative as mainframe software - but very innovative for personal use technology at the time, usable by a computer idiot and or a programmer. (Pascal is not comparable to Lisp - but Pascal is easily understood and highly functional). The small PC market disappeared as technology was rapidly released: things were no longer small.

The Corvus has Omninet (see below), a test chip to monitor the health of the computer and display graphs so you knew your computer is healthy, a BIOS too. Also the Corvus optionally had built-in BASIC to boot without a disk attached. Being an early release of a faster Motorola chip it was far faster than the original PC. The Corvus was HANDS DOWN a way better PC than an Intel / IBM PC and should have had that market. Unfortunately Corvus was not posed or inclined to challenge so many other companies that arrived to market: the market became very very saturated with heavy competitors, and mainframes technology was becoming released as small as PC and lowering in price.

This story isn't unique - that Corvus should have won the market but didn't sell. Many technologies of the 1980s were excellent, should have won out by virtue, but never sold enough units. Some of the most astounding technologies of computing still in wide use today couldn't sell enough units in the 80's and '90's.

Graphics

The Corvus has Mono Video Graphics Array and a large 8½" × 11" monitor that was very advanced: the video card was integrated in the monitor's update circuitry. Very "high res" for the day too. Reading text on that monitor was gem for those days (bright white with a hint of blue, clear, not blinky like the IBM) due to those advanced refresh technologies which the PC didn't match in full for several years. It was fast for the time. Having the video card circuit built right into the monitor circuit also came from the mainframe world.

Disk drives and backup

The company hacked the Apple II DOS to enable that home computer to use 10 MB Winchester technology hard disk drives. The Apple II normally was limited to the usage of 140 KB floppy disks. The Corvus disks not only increased the size of available storage but were also considerably faster than floppy disks. Typical usage ranged from small business and classroom management to data analysis. As an example the hard disks would be used for storing large mailing lists that could not fit on a floppy. Initial disk drives were sold to software engineers inside Apple Computer.

The disk drives were manufactured by IMI (International Memories Incorporated) in Cupertino, California. Corvus provided the hardware and software to interface them to Apple II's, Tandy TRS-80s, and S-100 bus systems. Later, IBM PCs and Macs were added to the list. These 5 MB and 10 MB drives were twice the size of a shoebox and initially retailed for US$5000. Corvus sold many stand alone drives whose numbers increased as they became shared over Omninet.

Certain models of the drives offered a tape backup option called "Mirror" to make hard disk backups using a VCR, which was itself a relatively new technology. A standalone version of "Mirror" was also made available. Data was backed up at roughly one megabyte per minute which resulted in five or ten minute backup times. Even though Corvus had a patent on this technology, several other computer companies later used this technique.

A later version of tape backup for the Corvus Omninet was called "The Bank" and was a standalone Omninet connected device that used custom backup tape media that were very similar in shape and size to today's DLT tapes.

Both the Corvus File Server and The Bank tape backup units were in white plastic housings roughly the size of two stacked reams of paper.

Networking

In 1980 Corvus came out with the first commercially successful local area network (LAN), called Omninet. Most Ethernet deployments of the time ran at 3 Mbit/s and cost one or two thousand dollars per computer. Ethernet also used a thick and heavy cable that felt like a lead pipe when bent, which was run in proximity to each computer, often in the ceiling plenum. A transceiver unit was spliced or tapped into the cable for each computer, with an additional AUI cable running from the transceiver to the computer itself.

Corvus's Omninet ran at one megabit per second, used twisted pair cables and had a simple add-in card for each computer. The card cost $400 and could be installed by the end user. Cards and operating software were produced for both the Apple II and the IBM PC and XT. At the time, many networking experts said that twisted pair could never work because "the bits would leak off"^{[citation needed]}, but it eventually became the de facto standard for wired LANs.

Other Omninet devices included the "Utility Server" that was an Omninet connected device that allowed one Parallel printer and two Serial devices (usually printers) connected to it to be shared on an Omninet network. Internally the Utility Server was a single-board Z80 computer with 64 kB of RAM, and on startup the internal boot ROM retrieved its operating program from the File Server. The literature/documentation and software that shipped with the Utility Server included a memory map and I/O ports writeup. Due to this, one popular hack was to replace the Utility Server's operating code file with a stand-alone copy of Wordstar configured for the serial port, and to fetch and save its files on the file server. Plug a dumb terminal into the first serial port, reboot the Utility Server and voilá!, Wordstar painted its startup screen and you had a cheap diskless word processing station.

A single Omninet was limited to 32 devices, and the device address was set with a 5-bit DIP switch. Device zero was the first file server, device one was the Mirror or The Bank tape backup, and two on up (to 31) were user computers, or Utility Servers. Systems with more than one file server had them at zero and up, then the tape backup, then the user computers. No matter what the configuration, you could only have 32 devices.

Corvus Concept

In April 1982, Corvus launched a computer called the Corvus Concept.^[1] This was a pizza-box Motorola 68000-based computer with a monitor mounted on its top, the first that could be rotated between landscape and portrait modes. Changing modes did not require rebooting the computer - it was all automatic and seamless and selected by a mercury switch inside the monitor shell. The first version of the Concept was limited to 1 MB of RAM, a simple hack provided 4 MB. The failure of the Concept was mostly related to the rise of the IBM PC, introduced the previous August.

Though not a GUI, the Concept used a standardized text user interface that made heavy use of function keys, with the current command performed by each key displayed on a persistent status line at the bottom of the screen.

Unix was later^[when?] ported to the Concept at which point it was somewhat similar to Sun's first workstation, which was launched in May 1982.

The Concept design was unique in that the entire motherboard could slide out of the back of the cabinet for easy upgrades, repairs and general access. The system was equipped with Apple II bus compatible slots for expansion cards. External 5.25" and 8" floppy disk drive peripherals (made by Fujitsu) were available for the Concept.

The system had a built in Omninet port on it. The system could boot from a locally connected floppy disk or Corvus Hard Drive or it could be booted over the Omninet network.

External links

• The Corvus Systems Museum

References

1. ^ Rich Zellich (1982-05-07). "Corvus Concept workstation". net.works. (Web link). Retrieved 2007-12-19.