Datapoint 2200

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Datapoint 2200

Manufacturer	Computer Terminal Corporation
Type	Personal computer
Casing	Plastic
Production	June, 1970
Discontinued	?
CPU	8-bit, made from discrete integrated chip components; nearly 100% compatible with Intel 8008
RAM	2 KB standard expandable to 16 KB
Graphics	Text only, 80×12 characters

The Datapoint 2200 was a mass-produced programmable terminal released by Computer Terminal Corporation (CTC) in June, 1970 (although some accounts say it was released sometime in 1971). It was intended by its designers simply to be a versatile, cost-efficient terminal for connecting to a wide variety of mainframes by loading various terminal emulations 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. CTC thus inadvertently invented the earliest known device that bears any significant resemblance to the modern personal computer. Equally significant is the fact that the terminal's CPU (processor) was the embryo of the x86 instruction set architecture, which powered the original IBM PC and has powered all of its descendents since.

1 Technical description
2 The seed of the x86 architecture
3 Credits
4 Specifications
5 External links

[edit] Technical description

The Datapoint 2200 had a built-in full-travel keyboard, a built-in 12-line, 80-column green screen monitor, and two tape drives. Its size (a B×W×H of roughly 2×2×1 ft) and shape (a cuboid box with protruding keyboard) approximated that of an IBM Selectric typewriter. Initially a Diablo 2.5Mb 2315-type removable cartridge hard disk drive was available, along with modems, several types of serial interface, parallel interface, printers and a punched card reader. Later, an 8-inch floppy disk drive was also made available, along with other, larger hard disk drives. In late 1977, local area networking through ARCnet became available. The original Type 1 2200 shipped with 2 kilobytes of serial shift register main memory, expandable to 8K. The Type 2 2200 used denser 1 kbit RAM chips, giving it a default 4K of memory, expandable to 16K. Its starting price was around US$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.

[edit] 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 microprocessor for the CPU, rather than a conventional processor built from discrete TTL modules. In 1969, CTC contracted two companies, Intel and Texas Instruments, 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, 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 instruction set 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 date.

[edit] Credits

The original instruction set architecture was developed by Victor Poor and Harry Pyle. The TTL design they ended up using was made by Gary Asbell. Industrial design (how the box's exterior looked, including the company's logo) was done by Jack Frassanito.

[edit] Specifications

Main unit

CPU: 8-bit, made from discrete integrated chip components; nearly 100% compatible with Intel 8008
RAM: 2K, expandable to 16K
Display: Text only, 80×12 characters
Storage: 2 tape drives, optional 8-inch Shugart floppy drive

Peripherals

Users of the 2200 and succeeding terminals eventually had several optional units to choose from. Among these were