84PCE:Ports:0000
From WikiTI
Synopsis
Port Number: 0000
Function: Controls interrupt speed and power
Bits [1:0]
Changing this changes the cursor blink rate. It's probably some kind of interrupt speed. 11b is slowest, 00b is fastest.
Bits [3:2]
Writes have no apparent effect, value does not latch.
Bit [4]
Set this bit to crash.
Bit [5]
Writes have no apparent effect, value does not latch.
Bit [6]
Set this bit to turn calc and screen off until next ON key.
Bit [7]
Latches value written, no apparent effect.