Texas Instruments TI-99/4A

The Texas Instruments TI-99/4A was an early home computer, released in June of 1981, originally at a price of USD $525. It was an enhanced version of the less-successful - and quite rare - TI-99/4 model released in late 1979 at a price of $1,150. The TI-99/4A added an additional graphics mode, "lowercase" characters comprised of small capitals, and a full travel keyboard. Its predecessor, the TI-99/4, featured a calculator-style chiclet keyboard and lacked any provision for lowercase text. The TI-99/4A's CPU, motherboard, and cartridge ("Solid State Software") slot were built into a single console, along with the keyboard. The power supply board (linear in early systems, switching in later systems) was housed below and in front of the cartridge slot under the sloped area to the right of the keyboard. Available peripheral included a 5¼" floppy disk drive and controller, an RS-232 card comprising two serial port and one parallel port, a P-Code card for PASCAL support, a thermal... full article at wikipedia