Datapoint 2200
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The Datapoint 2200 was a programmable terminal released by Computer Terminal Corporation (CTC) in June 1970. (Some accounts say it was released sometime in 1971.) Intended 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, users suddenly realized these programmable terminals could be made to perform other tasks as well. (The first one being Pillsbury Foods.) CTC thus inadvertently invented what is now generally accepted to be the first personal computer. Equally significant is that the terminal's CPU (processor) was the embryo of the x86 instruction set architecture.
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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 electric typewriter. An optional 8-inch floppy disk drive was available, then modems, printers and hard disk drives, and in late 1977, local area networking through ARCnet became available. The original Type 1 2200 shipped with 2 kilobytes of 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. The 2200 models were succeeded by the 5500, 6600, 3800, 8800, etc.
The seed of the x86 architecture
Aside from being the first personal computer, 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.
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) was done by Jack Frassanito.
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
- modems
- hard disks
- printers
- ARCnet LAN
External links
- Information about the Datapoint 2200 at OLD-COMPUTERS.COM (http://www.old-computers.com/museum/computer.asp?st=1&c=596) – Including a picture of the terminal