Datapoint 2200
Encyclopedia
The Datapoint 2200 was a mass-produced programmable terminal
Computer terminal
A computer terminal is an electronic or electromechanical hardware device that is used for entering data into, and displaying data from, a computer or a computing system...

, designed by Phil Ray and Gus Roche, announced by Computer Terminal Corporation (CTC)
Datapoint
Datapoint Corporation, originally known as Computer Terminal Corporation , was a computer company based in San Antonio, Texas, United States. Founded in 1967 by Phil Ray and Gus Roche, its first products were, as the company's initial name suggests, computer terminals...

 in June, 1970 (with units shipping in 1971). It was intended by its designers simply to be a versatile, cost-efficient terminal for connecting to a wide variety of mainframe
Mainframe computer
Mainframes are powerful computers used primarily by corporate and governmental organizations for critical applications, bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.The term originally referred to the...

s by loading various terminal emulation
Emulator
In computing, an emulator is hardware or software or both that duplicates the functions of a first computer system in a different second computer system, so that the behavior of the second system closely resembles the behavior of the first system...

s from tape rather than being hardwired as most terminals were. However, enterprising users in the business sector (including Pillsbury Foods) realized that this so-called "programmable terminal" was equipped to perform any task a simple computer could, and exploited this fact by using their 2200s as standalone computer systems. Equally significant is the fact that the terminal's multi-chip CPU
Central processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...

 (processor) became the embryo of the x86 architecture which the original IBM PC
IBM PC
The IBM Personal Computer, commonly known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. It is IBM model number 5150, and was introduced on August 12, 1981...

 and its descendants are based on.

Technical description

The Datapoint 2200 had a built-in full-travel keyboard
Computer keyboard
In computing, a keyboard is a typewriter-style keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches...

, a built-in 12-line, 80-column green screen monitor, and two cassette tape drives each with 130 KB
Kilobyte
The kilobyte is a multiple of the unit byte for digital information. Although the prefix kilo- means 1000, the term kilobyte and symbol KB have historically been used to refer to either 1024 bytes or 1000 bytes, dependent upon context, in the fields of computer science and information...

 capacity. Its size (approx. 2w×2d×1h ft) and shape (a box with protruding keyboard) approximated that of an IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...

 Selectric typewriter
Typewriter
A typewriter is a mechanical or electromechanical device with keys that, when pressed, cause characters to be printed on a medium, usually paper. Typically one character is printed per keypress, and the machine prints the characters by making ink impressions of type elements similar to the pieces...

. Initially a Diablo
Diablo Data Systems
Diablo Data Systems was a division of Xerox created by the acquisition of Diablo Systems Inc. in 1972.It is best known for the Diablo 630 daisywheel printer, but also produced the hard disk drives that were resold by DEC as the RK02 and RK03....

 2.5 MB 2315-type removable cartridge hard disk drive was available, along with modems, several types of serial interface, parallel interface, printers
Computer printer
In computing, a printer is a peripheral which produces a text or graphics of documents stored in electronic form, usually on physical print media such as paper or transparencies. Many printers are primarily used as local peripherals, and are attached by a printer cable or, in most new printers, a...

 and a punched card
Punched card
A punched card, punch card, IBM card, or Hollerith card is a piece of stiff paper that contains digital information represented by the presence or absence of holes in predefined positions...

 reader. Later, an 8-inch floppy disk
Floppy disk
A floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic carrier lined with fabric that removes dust particles...

 drive was also made available, along with other, larger hard disk
Hard disk
A hard disk drive is a non-volatile, random access digital magnetic data storage device. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the...

 drives. An industry-compatible 7/9-track (user selectable) magnetic tape drive was available by 1975. In late 1977, Datapoint introduced ARCnet
ARCNET
ARCNET is a local area network protocol, similar in purpose to Ethernet or Token Ring. ARCNET was the first widely available networking system for microcomputers and became popular in the 1980s for office automation tasks...

 local area network
Local area network
A local area network is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory, or office building...

ing. The original Type 1 2200 shipped with 2 kilobyte
Kilobyte
The kilobyte is a multiple of the unit byte for digital information. Although the prefix kilo- means 1000, the term kilobyte and symbol KB have historically been used to refer to either 1024 bytes or 1000 bytes, dependent upon context, in the fields of computer science and information...

s of serial shift register main memory, expandable to 8K. The Type 2 2200 used denser 1 kbit
Kilobit
The kilobit is a multiple of the unit bit for digital information or computer storage. The prefix kilo is defined in the International System of Units as a multiplier of 103 , and therefore,...

 RAM
Random-access memory
Random access memory is a form of computer data storage. Today, it takes the form of integrated circuits that allow stored data to be accessed in any order with a worst case performance of constant time. Strictly speaking, modern types of DRAM are therefore not random access, as data is read in...

 chips, giving it a default 4K of memory, expandable to 16K. Its starting price was around US$
United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....

5,000, and a full 16K Type 2 2200 had a list price of just over $14,000. The 2200 models were succeeded by the 5500, 1100, 6600, 3800, 8800, etc.

The seed of the x86 architecture

Aside from being one of the first personal computers, the Datapoint 2200 has another connection to computer history. Its original design called for a single-chip 8-bit
8-bit
The first widely adopted 8-bit microprocessor was the Intel 8080, being used in many hobbyist computers of the late 1970s and early 1980s, often running the CP/M operating system. The Zilog Z80 and the Motorola 6800 were also used in similar computers...

 microprocessor
Microprocessor
A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...

 for the CPU
Central processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...

, rather than a conventional processor built from discrete TTL
Transistor-transistor logic
Transistor–transistor logic is a class of digital circuits built from bipolar junction transistors and resistors. It is called transistor–transistor logic because both the logic gating function and the amplifying function are performed by transistors .TTL is notable for being a widespread...

 modules. In 1969, CTC contracted two companies, Intel and Texas Instruments
Texas Instruments
Texas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...

, to make the chip. TI was unable to make a reliable part and dropped out. Intel was unable to make CTC's deadline. Intel and CTC renegotiated their contract, ending up with CTC keeping its money and Intel keeping the eventually completed processor.

CTC released the Datapoint 2200 using about 100 discrete TTL components (SSI/MSI chips) instead of a microprocessor, while Intel's single-chip design, eventually designated the Intel 8008
Intel 8008
The Intel 8008 was an early byte-oriented microprocessor designed and manufactured by Intel and introduced in April 1972. It was an 8-bit CPU with an external 14-bit address bus that could address 16KB of memory...

, was finally released in April 1972. The 8008's seminal importance lies in its becoming the ancestor of Intel's other 8-bit CPUs, which were followed by their assembly language compatible 16-bit CPU's—the first members of the x86-family, as the instruction set was later to be known. Thus, CTC's engineers may be said to have fathered the world's most commonly used and emulated instruction set architecture from the mid-1980s to .

Credits

The original instruction set architecture was developed by Victor Poor and Harry Pyle. The TTL
Transistor-transistor logic
Transistor–transistor logic is a class of digital circuits built from bipolar junction transistors and resistors. It is called transistor–transistor logic because both the logic gating function and the amplifying function are performed by transistors .TTL is notable for being a widespread...

 design they ended up using was made by Gary Asbell. Industrial design
Industrial design
Industrial design is the use of a combination of applied art and applied science to improve the aesthetics, ergonomics, and usability of a product, but it may also be used to improve the product's marketability and production...

 (how the box's exterior looked, including the company's logo) was done by Jack Frassanito.

Specifications

Main unit
  • CPU: 8-bit, made from standard TTL
    Transistor-transistor logic
    Transistor–transistor logic is a class of digital circuits built from bipolar junction transistors and resistors. It is called transistor–transistor logic because both the logic gating function and the amplifying function are performed by transistors .TTL is notable for being a widespread...

     components. The Intel 8008
    Intel 8008
    The Intel 8008 was an early byte-oriented microprocessor designed and manufactured by Intel and introduced in April 1972. It was an 8-bit CPU with an external 14-bit address bus that could address 16KB of memory...

     was a nearly 100% compatible LSI implementation.
  • RAM: 2K, expandable to 16K
  • Display: Text only, 80×12 characters
  • Storage: 2 tape drives, optional 8-inch Shugart
    Shugart
    Shugart is the de facto standard for floppy disk drive interfaces created by Shugart Associates.* 50 pin: 8"* 34 pin: 5¼", 3½", 3""Shugart" may also refer to the company Shugart Associates, the founder of Shugart Associates, Alan Shugart, or political scientist Matthew Søberg Shugart....

     floppy drive


Peripherals

Users of the 2200 and succeeding terminals eventually had several optional units to choose from. Among these were
  • modems
    Modem
    A modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data...

  • hard disks
  • printers
  • ARCnet LAN
    ARCNET
    ARCNET is a local area network protocol, similar in purpose to Ethernet or Token Ring. ARCNET was the first widely available networking system for microcomputers and became popular in the 1980s for office automation tasks...


External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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