TI-99/4A FAQ: Power Supplies

External Power Supplies:

  • TI-99/4A USA: 

Internal Power Supplies:

Power supply from a 99/4 (NOTE: NOT COMPATIBLE WITH 4/A)

Power supply from a 99/4A

Power supply from a 99/4A QI

 

This is the connector on the back of the console that the ac adapter plugs into. Some of these connectors have 4 pins, while others have 3. The newer power supplies (QI) only have 2 pins. They way they were set up you can use any ac adapter with any of the consoles.

The AC voltages in are:

1. Black 8 volt

2. White 16 volt

3. Red 5 volt

4. No connection

The power supply is a very standard setup, and could be replaced by any standard PC power supply.

The DC voltages out are:

Pin 1 = -5 volt

Pin 2 = +12 volt

Pin 3 = GND

Pin 4 = +5 volt.

 

Schematic for power supply (not QI)

Here is an interesting project replacing the console power supplies with a new board:

 

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