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.

SE Calculator Ports Only

Port 0A: Writing:

• Tied to the link assist on the SE calculators. Only written to in the boot code where it receives B4.
  • If this is set to DF or above, ti-connect won't detect the calculator over silver link.

Port 0B:

• Tied to the link assist on the SE calculators. Only written to in boot code where it receives B4. Possibly controls the timeout for receiving.

Port 0C:

• Tied to the link assist on the SE calculators. Only written to in boot code where it receives B4. Possibly controls the timeout for sending.
  • If this is set to E0 or above, the link assist won't throw an error if you write to port 0D without another calculator attached.

Port 2D:

• Only bits 0 and 1 can be altered, but no effect is apparent. Only written to in the boot code, where it receives 02.

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