This page will serve to chronicle my work with the TI99/4a vintage home computer system by Texas Instruments (c 1981)

The TI99 is a "vintage" home computer system from 1981 made by Texas Instruments. You can probably search all the details about it on the wikipedia or google but the main thing to note was that it hooked up to your TV and didn't require any sort of special monitor. Since first experimenting with them in 2005, I have beenable to get them to glitch out to audio and other digital signals. This process started with straight jumpering one device to another and then evolved into custom circuitry mods. What I have not done is program the device to do any of the things it does.

More of My History with Bending and the TI99



Version 4

Features ::
3 light sensors with adjustable threshold controls
4 band audio reativity circuitry with independent threshold controls (low, mid, hi, full frequency)
4 independent oscillators
1 Audio enable switch
3 mode oscillator selection (manual, light controlled, sound controlled)
2 composite video outputs
1/4" Unbalanced Audio Input
1/4" Unbalanced Audio Output
Volume Control

images ::
Image-001 :: Glam shot
Image-002 :: Mills College exchange concert performance setup (side)
Image-003 :: Mills College exchange concert performance setup (front)
Image-004 :: Populated Hand Etched Board (top)
Image-005 :: Populated Hand Etched Board (top)
Image-006 :: Wiring
Image-007 :: Light Sensors
manual-v4 :: Manual

video ::
example-001 :: Light sensors are used to alter the video content and audio output. The audio simultaneously influences the video output as well.
example-002 :: A jam using the light sensors and manual oscillator switching
example-003 :: Hands-off circular content generation
example-004 :: Demonstration of the manual oscillator switching process
example-005 :: Demonstration of the lightsensor interface



Version 3

Features ::
4 band audio reactivity with adjustable threshold controls (sub, low, mid ,hi)
4 independent oscillators
4 dual input ring modulators
24 point signal routing patchbay
1/4" audio input
1/4" audio output
composite video output
volume
2 "glitch" buttons

images ::
Image-001 :: Top View
Image-002 :: Glam Shot
Image-003 :: Left Side
Image-004 :: Right Side
Image-005 :: Circuit in Progress
Image-006 :: Body and Circuit in Progress
Image-007 :: Breadboarded Mod

video ::
example-001 :: Mixer facilitated feedback
example-002 :: Mixer facilitated feedback
example-003 :: Mixer facilitated feedback
example-004 :: Mixer facilitated feedback
example-005 :: Ouroboros - V


Version 2

Features ::
3 band audio reactivity with threshold controls (low, mid, high)
4 9-point rotary switches for glitch point selection
4 toggles for glitch point interconnection
1/4" audio input
composite video out
4 point patchbay with patch enable toggles for connection of external devices

images ::
Image-001 :: Glam shot
Image-002 :: Audio Controls
Image-003 :: I/O and Controls
Image-004 :: I/O
Image-005 :: Wiring in Progress
Image-006 :: Breadboard in Progress
text-001 :: Text Art
text-002 :: Text Art
text-003 :: Text Art
text-004 :: Text Art
text-005 :: Text Art
text-006 :: Text Art
text-007 :: Text Art
text-008 :: Text Art
text-009 :: Text Art
text-010 :: Text Art
text-011 :: Text Art
text-012 :: Text Art

video ::
example-001 :: Glitching to Deadelus
example-002 :: Glitching to Deadelus
example-003 :: "Mind Meld" with Joystick Synth
example-004 :: "Mind Meld" with Casio SK-1
example-005 :: "Mind Meld" with Casio SK-1


Version 1

Features ::
2 9-point and 4 12-point rotary switches for glitch point selection
9 toggles for glitch point interconnection
4 point patchbay with toggle enable for connection to external devices
4 glitch switches
composite video out

images ::
Image-001.jpg :: Top
Image-002.jpg :: Performance Rig
Image-003.jpg :: Guts

video ::
example-001 :: "Mind Meld" with Joystick Synth



Prototype

Features ::
2 9-point and 4 12-point rotary switches for glitch point selection
10 toggles for glitch point interconnection
12 point patchbay for connection to external devices
8 toggles for patch enable
composite video out

images ::
Image-001.jpg :: Top
Image-002.jpg :: Performance Rig
Image-003.jpg :: Guts
Image-004.jpg :: Guts
Image-005.jpg :: Screen Still
Image-006.jpg :: Screen Still
Image-007.jpg :: Screen Still
Image-008.jpg :: Screen Still
Image-009.jpg :: Screen Still

video ::
example-001 ::
example-002 ::