Category:83Plus:Ports:Unknown

Synopsis

There are several ports that have not yet been totally solved. Here is a list of them and what information is available.

83+ & SE Calculator Ports

• Bits 6, and 7: "Low battery" level is not known. It would be great if somebody with a finely-variable voltage DC power supply tested this. The values are probably controlled using external resistors, because the TI-84+CSE's lithium-ion battery operates at a completely different voltage level.

SE Calculator Ports Only

Port 17: This always reads 0, and writing to it produces no apparent effect. It's a bit suspicious, because all the ports before it and after it have a purpose.

Ports 39 and 3A:

• These ports seem to control GPIO pins, but exactly what those pins connect to is a mystery.

Port 3B: Very like does nothing.

Ports 3C-3F:

• On DrDnar's TI-84+CSE, these read 78, yet on a TI-84+SE with the TA3 ASIC, they read 00.

USB Ports:

• All information concerning the USB ports will be handled here.

Comments

Other ports have unknown functions but are never written to, read from, or change in a significant way, some likely have no purpose at all.

There is still quite bit unknown about the hardware, however the remainder is less significant to or can not be used by the average coder.

Credits and Contributions

• Tijl Coosemans
• Dan Englender
• James Montelongo
• Michael Vincent