Back to index

Info for ti99_4a


Texas Instruments TI-99/4a Home Computer

Known Issues:
Requires full keyboard emulation. At startup, full keyboard emulation mode is
enabled by default. Whilst in full keyboard emulation mode, some key
associated functionality may be disabled (like the ESC key for EXIT).
The keyboard emulation mode is toggled using the scroll_lock key.

Usage:
This TI99/4a driver offers a high level of compatibility. It currently
supports V9t9-format cartridge images, sampled tapes in wave format
(CS1 and CS2), and up to 3 SSSD disk images. Speech synthesis is emulated,
although speech ROM emulation is still in the works. TI, Super AMS and
Foundation memory expansion cards are supported.

Loading a cartridge:
You do not need a cartridge image to run the computer, since TI99/4a has
a small built-in basic interpreter.
V9t9-format cart images are typically split into up to 3 files. These can be
loaded in any order, so long as all necessary portions are loaded.

Setting up the system configuration:
A few dip switches enable or disable computer extensions. These switches are
only read at reset. Therefore, if you edit them, you must reset the emulator
(press F3 in partial keyboard emulation mode) for the changes to be taken
into account.

History and Trivia:
The TI99/4a Home Computer was a TI99/4 with improved keyboard, revised
ROMs, and an additional graphics mode. It was officially introduced in
June 1981, and was retired in late 1983.
TI99/4a was quite successful in Europe and US (possibly hundreds of
thousand units built). In 1983, though, competition on the home computer
market was so harsh that TI had to cut down the price of TI99/4a to less
than $100, while suffering heavy losses. So, by the end of 1983, TI had
abandoned TI99/4a, its prototype successors, and withdrawn from the home
computer market.


created on Mon Dec 09 08:16:57 2002