83Plus:Ports:4A

This port only exists on the the TI-84 Plus and the TI-84 Plus Silver Edition. On the standard TI-83 Plus, it acts as a shadow of port 0A. On the TI-83 Plus Silver Edition, this port has no effect.

Synopsis

Port Number: 4A

Function: USB Line Control

Using this port, you can control the D+ from an A-type connector and the D− line from a B-type connector.

Read Values

• Bit 0: Set if connected to computer.
• Bit 1: Set if not connected to computer. Flashes when talking to computer.
• Bit 2: Set if not connected to computer.
• Bit 3: If set, the corresponding line is forced high. Max 0.79 mA.
• Bit 4: Only significant if bit 3 is set. If this is set, the corresponding line gets extra power. Max total 1.52 mA.
• Bit 5: Reset means the corresponding line is getting 0.05 V at 15μA.
• Bit 6: Always 0
• Bit 7: Always 0

Write Values

• Bits 0-2: No effect
• Bit 3: Set to force the corresponding line. Max output: 0.79 mA.
• Bit 4: If bit 3 is set. Setting this give the corresponding line extra power. Max total output 1.52 mA.
• Bit 5: Resetting this gives the corresponding line 0.05 V at 15μA.
• Bits 6-7: No effect

Comments

If you don't like USB protocol, you could try to use this port for communication, or maybe as a "ready" signal. Anyways, when you are done, output 20h.