Updated 20170101


CaDD PC99 Suite is a software-only package that includes:

    • PC99W. A Windows program that emulates the Texas Instruments TI-99/4A Home Computer and selected TI and third-party peripherals.
    • PC99W Config. A Windows program that lets you specify the components to be emulated by PC99W.
    • PC99W Disk Utilities. A Windows program that lets you catalog and manipulate emulated TI diskette files.
    • The Cyc. This contains all known TI modules and disks, and many, many other files.

The Cyc details

  • a99 Assembler. A freeware TI-99/4A cross-assembler.
  • PC99 DOS. This is based on PC99 Stage 6 Full. For Windows 7 and higher this requires the freeware program DOSBox. PC99 DOS is supplied for “legacy” users.
  • CaDD Launcher. A program that allows quick selection of CaDD PC99 Suite programs.

Supported PC operating systems

  • Microsoft Windows XP.
  • Microsoft Windows 7.
  • Microsoft Windows 10.

Note: Not tested with Windows 2000, Windows Vista, or Windows 8 or 8.1. There is no theoretical reason why the CaDD PC99 Suite should not work on these operating systems.

Required hardware

Personal computer with:

  • Intel Pentium 5 3.0 GHz or higher recommended.
  • 4 GB Memory minimum recommended.
  • 1280 x 1024 graphics or better.
  • Hard drive with at least 1 GB space free.
  • DVD-R or DVD-RW optical drive | USB 2.0 or higher port.
  • Optional: COM port | USB->COM adapter, if transferring disks from TI to PC.

Required software

  • A supported version of Microsoft Windows with DirectX.
  • An “unzip” program such as 7-Zip or WinZip.
  • A program that can read Adobe Portable Document (.pdf) files.
    Ex: Adobe Reader, free from Adobe
  • A program that can read ASCII text files. Ex: Notepad, which is included with Windows.
  • The ability to start and be able to use a command prompt on your PC.


See the CaDD PC99 Suite overview and installation documentation:

“CaDD PC99 Suite overview and installation”


Until the release of CaDD PC99 Suite, CaDD offered PC99 Stage 6 {Full | Light} and The Cyc separately. Because of licensing arrangements with Texas Instruments and third-party vendors, you had to be an owner of PC99 Stage 6 {Full | Light} to order The Cyc. By bundling PC99 DOS, the PC99W emulator, and The Cyc in CaDD PC99 Suite, this restriction no longer applies.