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This port only exists as a distinct port on the TI-83 Plus Silver Edition, the TI-84 Plus, and the TI-84 Plus Silver Edition. On the standard TI-83 Plus, it acts as a shadow of port 02.


Port Number: 2Ah

Function: LCD Delay (15 MHz)

This port works in the same manner 29 does, but only when the calculator is set at 15mhz and if port 20 equals 01. It removes the amount of delay needed between accesses to the lcd driver by adding a delay to any instruction which reads from or writes to ports 10 or 11, as well as the mirror ports 12 and 13.


  • Bit 0 enables the effects of the flash delay controlled by port 2E.
  • Bit 1 enables the effects of the ram delay controlled by port 2E.
  • Bits 2-7 control the amount of delay added at specified instructions. To calculate the number of clock cycles added divide the contents of port 2A by 4 and round off. NOTE: The contents of this port should NOT be less than 0Ch or the LCD driver will no longer respond.


This port is not available on the normal TI-83+. On the normal TI-83+ this port is a shadow of Port 02h.

The effect of this port is only seen if the contents of port 20h equals 01.

Credits and Contributions

  • Michael Vincent: Documentation as found here.
  • James Montelongo: Documentation found at here.