Datapoint 3300
| Type | Computer terminal |
|---|
The DataPoint 3300 was the first computer terminal manufactured by Computer Terminal Corporation, later renamed Datapoint, announced in 1967[1] and shipping in 1969.[2] Since this terminal was intended to replace a teleprinter such as those made by Teletype Corporation it was one of the first glass TTYs (glass for the screen, TTY as the abbreviation for "Teletype") ever produced.
As well as being sold under its own name, it was also sold as the DEC VT06 and the HP 2600A (introduced in 1972).[3]
Details
The Datapoint 3300 emulated a Teletype Model 33, but went beyond what a Teletype could achieve with its paper output. It supported control codes to move the cursor up, down, left and right, to the top left of the screen, or to the start of the bottom line. The 3300 could also clear to the end of the current line, or clear to the end of the screen.
It did not, however, support direct cursor positioning. It also had 25 rows of 72 columns of upper-case characters, rather than the 80 x 24 that would become more common in subsequent years.
Hardware
Like most terminals designed up until the mid 1970s, the Datapoint 3300 was implementated using TTL logic in a typical mix of small-scale and medium-scale integrated circuits,[4] i.e. in a very similar way to how many mini-computers of the 1970/80s (such as the Digital VAX-11) were built. Later terminals (such as the VT100) typically used a microprocessor to implement large parts of the user interface and general logic.
At the time of its introduction, RAM was expensive (it would not be until 1970 that Intel released the 1103, the first DRAM semiconductor memory chip making RAM affordable). Thus, the terminal stored its display of 25 rows of 72 columns of upper-case characters using fifty-four 200-bit shift registers, arranged in six tracks of nine packs each, providing storage for 1800 6-bit characters.[4] The shift-register design meant that scrolling the terminal display could be accomplished by simply pausing the display output to skip one line of characters.
References
- ^ The History of the TV Typewriter, Michael Holley
- ^ Alan Weinkrantz (June 2, 2009). "San Antonio Has Claim As The Birthplace of the Personal Computer. Read All About It". Archived from the original on January 13, 2014.
- ^ HP Computer Museum page on HP 2600A, access Dec 26, 2010
- ^ a b DataPoint 3300 Maintenance Manual, December, 1976.
See also
External links
- Datapoint documentation on bitsavers.org
- Page with links to a doctoral thesis about early microprocessor history, with lots of details about Datapoint's role, and a copy of the Datapoint 2200 Programmer's Guide (both in PDF format) – both with a lot of historical detail.
- The man who invented the PC
- Unofficial Datapoint Organization WEB site at datapoint.org