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DC100
DC100 (also known as DC100A) is a tape cartridge format that was co-developed by Hewlett-Packard and 3M. Introduced in mid-1976, it was developed as a data storage mechanism for the HP 9820 programmable calculator. The DC100 tape cartridge was a scaled-down version of the DC300 cartridge pioneered by 3M, and represents an early version of what is now referred to as the QIC Mini Cartridge. 3M was the exclusive source of DC100 tapes, while drives were manufactured by 3M and several third parties. History The DC100 tape cartridge format was used in the HP desktop calculator and computer systems of the late 1970s and early 1980s, including the 9815, 9825, 9845, and HP series 80. HP also used it in their 2640 series of computer terminals. Tape transports were manufactured by 3M, as well as North Atlantic Qantex, Instrumentation Technology Corporation, and Beehive International. Outside of HP, the format suffered from poor adoption rates four years after its introduction, accordi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HP Series 80
The Hewlett-Packard series 80 of small scientific desktop computers was introduced in 1980, beginning with the popular HP-85 targeted at engineering and control applications. They provided the capability of the HP 9800 series desktop computers with an integrated monitor in a smaller package including storage and printer, at half the price. Features The first model of the Series 80 was the HP-85, introduced in January 1980. '' BYTE'' wrote "we were impressed with the performance ... the graphics alone make this an attractive, albeit not inexpensive, alternate to existing small systems on the market ... it is our guess that many personal computer experimenters and hackers will want this machine." In a typewriter-style desktop case, the HP-85 contains the CPU and keyboard, with a ROM-based operating system (like the 9800 series), 16 KB dynamic RAM, a 5-inch CRT screen (16 lines of 32 characters, or 256×192 pixels), a tape drive for DC-100 cartridges ( capacity, transfer), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DECtape
DECtape, originally called Microtape, is a magnetic tape data storage medium used with many Digital Equipment Corporation computers, including the PDP-6, PDP-8, LINC-8, PDP-9, PDP-10, PDP-11, PDP-12, and the PDP-15. On DEC's 32-bit systems, VAX/VMS support for it was implemented but did not become an official part of the product lineup. DECtapes are 3/4 inch (19 mm) wide, and formatted into blocks of data that can each be read or written individually. Each tape stores 184K 12-bit PDP-8 words or 144K 18-bit words. Block size is 128 12-bit words (for the 12-bit machines), or 256 18-bit words for the other machines (16, 18, 32, or 36 bit systems). From a programming point of view, because the system is block-oriented and allows random seeking, DECtape behaves like a very slow disk drive. Origins DECtape has its origin in the LINCtape tape system, which was originally designed by Wesley Clark at the MIT Lincoln Laboratory as an integral part of the LINC computer. There ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irwin Magnetic Systems
Irwin Magnetic Systems was a computer storage manufacturer founded in 1979 and based in Ann Arbor, Michigan. At its height, the company employed 600 people in Ann Arbor. The company's primary product line was magnetic tape data storage systems, particularly the proprietary AccuTrak format. This format was widely adopted by Compaq, HP and other OEM manufacturers, and was also incorporated into IBM Personal System 2 (PS2) personal computers as an option. In 1989, the company was acquired by Cipher Data Products, which was in turn acquired by Archive Corporation Archive Corporation was a computer tape drive manufacturer, based in Costa Mesa, California, that was acquired by Conner Peripherals in 1993. History The company was founded in 1980 and based out of Costa Mesa, California. The company employed 3,3 ... a year later. Archive maintained Irwin as an independent brand for a while after the acquisition. Notable products * EzTape - Backup/Restore Software * AccuTrak Plus 12 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Degree (angle)
A degree (in full, a degree of arc, arc degree, or arcdegree), usually denoted by ° (the degree symbol), is a measurement of a plane angle in which one full rotation is 360 degrees. It is not an SI unit—the SI unit of angular measure is the radian—but it is mentioned in the SI brochure as an accepted unit. Because a full rotation equals 2 radians, one degree is equivalent to radians. History The original motivation for choosing the degree as a unit of rotations and angles is unknown. One theory states that it is related to the fact that 360 is approximately the number of days in a year. Ancient astronomers noticed that the sun, which follows through the ecliptic path over the course of the year, seems to advance in its path by approximately one degree each day. Some ancient calendars, such as the Persian calendar and the Babylonian calendar, used 360 days for a year. The use of a calendar with 360 days may be related to the use of sexagesimal numbers. Anothe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fixture (tool)
A fixture is a work-holding or support device used in the manufacturing industry. Fixtures are used to securely locate (position in a specific location or orientation) and support the work, ensuring that all parts produced using the fixture will maintain conformity and interchangeability. Using a fixture improves the economy of production by allowing smooth operation and quick transition from part to part, reducing the requirement for skilled labor by simplifying how workpieces are mounted, and increasing conformity across a production run. A fixture differs from a jig in that when a fixture is used, the tool must move relative to the workpiece; a jig moves the piece while the tool remains stationary. Purpose A fixture's primary purpose is to create a secure mounting point for a workpiece, allowing for support during operation and increased accuracy, precision, reliability, and interchangeability in the finished parts. It also serves to reduce working time by allowing quick set- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oersted The oersted (symbol Oe) is the coherence (units of measurement), coherent derived unit of the Magnetic field#The H-field, auxiliary magnetic field H in the centimetre–gram–second system of units (CGS). It is equivalent to 1 dyne per maxwell (unit), maxwell. Difference between CGS and SI systems In the CGS system, the unit of the H-field is the oersted and the unit of the B-field is the gauss (unit), gauss. In the SI system, the unit ampere per meter (A/m), which is equivalent to newton (unit), newton per weber (unit), weber, is used for the H-field and the unit of tesla (unit), tesla is used for the B-field. History The unit was established by the International Electrotechnical Commission, IEC in the 1930s in honour of Danish physicist Hans Christian Ørsted. Ørsted discovered the connection between magnetism and electric current when a |
