Texas Instuments TI-99/4A
Home Computer

TI-99/4AMy first computer was a TI-99/4A. Actually, my current computer is a TI-99/4A. Call me "trailing-edge". No, but I still use it for keeping my budget (Multiplan), programming (assembly and C99 and BASIC for little jobs), and (duh) games.

  • Based on the TMS9900 processor, perhaps the first commercially useful 16-bit microprocessor. Interesting that the CPU has only three registers; Program Counter, Status Register, and a Workspace Pointer, which points to a block of 16 general-purpose registers that live in memory! Beautiful mainframe-style assembly code, unique bit-wise I/O operations, no built-in stack!
  • Plus, the TMS9900 is the same family and has the same (mostly) instruction set and development tools as the SBP9989, the processor in the (old) TOW missile launcher, which I helped with quite a bit during the Hughes Aircraft days!
  • I've got three in use: the computer nook, my workshop (for H/W playing), and at my office at work (quite the conversation piece). I've also got a Geneve 9640 "Second Generation TI" based on the TMS9995, but I don't use it right now 'cause the obsolete monitor is dead, and I'm waiting for some free time (hah!) to attempt to connect it to a Sony Multisync 2 I've got.

Texas Instruments Logo

TI's history page

Kilby and TI-99/4ATI's most famous son, Jack Kilby, inventor of the integrated circuit, posing with TI's products such as the calculators developed to utilize the newly-invented integrated circuit, and the TI-99/4A!

PROJECTS:

  • Sudoku puzzle solver (TIFILES format, ARC303 compressed)
    "Same as" project on DOS page, ported to C99.
  • Sega Genesis Controller hack
    How to modify a Sega Genesis 3-button controller for use on a TI. Still need an Atari-to-TI joystick adapter (project coming).