83Plus:Ports:4B

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 03. On the TI-83 Plus Silver Edition, this port has no effect.

Synopsis

Port Number: 4B

Function: USB power

This has something to do with the USB power (+5 VDC) line.

Bits

All bits are read-only, except bit 5.

• Bit 0: Perhaps indicates if there's voltage on the line?
• Bit 1: Unknown function
• Bit 2: Perhaps indicates if there's NOT voltage on the line?
• Bit 3: Means something, possibly change in Vcc?
• Bit 4: Possibly means charge pump is active?
• Bit 5: Set to possibly enable charge pump? Related to some GPIO pins. If bit 4 is unimportant, then this bit needs to be futzed with manually to make the charge pump work.
• Bit 6: Possibly the OR of bits 4 and 5?
• Bit 7: No function

Comments

This is mostly speculation.