Difference between revisions of "83Plus:Ports:2F"

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m (Foregot SE only)
(Remaining bits plus more accurate timing)
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=== Write Values ===
 
=== Write Values ===
−
* Bits 0 and 1 control the amount time, the following values tell by how much.  
+
* Bits 2-4 contorl the amount of time when port 20 contains 1. The following values tell the amount of time.
−
** 0 = ~3.5 microseconds
+
** 00 = ~3.2 microseconds
−
** 1 = ~8 microseconds
+
** 01 = ~7.4 microseconds
−
** 2 = ~10.5 microseconds
+
** 10 = ~11.7 microseconds
−
** 3 = ~15 microseconds
+
** 11 = ~16.0 microseconds
  
−
*Bits 2-7: The function of these bits are unknown.
+
* Bits 2-4 contorl the amount of time when port 20 contains 2. The following values tell the amount of time.
 +
** 000 = ~3.2 microseconds
 +
** 001 = ~7.4 microseconds
 +
** 010 = ~11.7 microseconds
 +
** 011 = ~16.0 microseconds
 +
** 100 = ~20.2 microseconds
 +
** 101 = ~24.5 microseconds
 +
** 110 = ~28.8 microseconds
 +
** 111 = ~33.0 microseconds
 +
 
 +
* Bits 5-7 contorl the amount of time when port 20 contains 3. The following values tell the amount of time.
 +
** 000 = ~3.2 microseconds
 +
** 001 = ~7.4 microseconds
 +
** 010 = ~11.7 microseconds
 +
** 011 = ~16.0 microseconds
 +
** 100 = ~20.2 microseconds
 +
** 101 = ~24.5 microseconds
 +
** 110 = ~28.8 microseconds
 +
** 111 = ~33.0 microseconds
  
  
 
== Comments ==
 
== Comments ==
−
'''NOTE:''' The timings above are ROUGHLY estimated.
 
  
 
This value really shouldn't be changed. TI-OS depends on this being set high enough to function for the LCD delay.
 
This value really shouldn't be changed. TI-OS depends on this being set high enough to function for the LCD delay.

Revision as of 05:03, 23 August 2005

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 07.

Synopsis

Port Number: 2Fh

Function: LCD Wait Delay

After every write to the LCD bit 1 of port 2 resets for a certain amount of time. This port controls that amount time.


Read Values

  • This port reads the last vaule written to it.


Write Values

  • Bits 2-4 contorl the amount of time when port 20 contains 1. The following values tell the amount of time.
    • 00 = ~3.2 microseconds
    • 01 = ~7.4 microseconds
    • 10 = ~11.7 microseconds
    • 11 = ~16.0 microseconds
  • Bits 2-4 contorl the amount of time when port 20 contains 2. The following values tell the amount of time.
    • 000 = ~3.2 microseconds
    • 001 = ~7.4 microseconds
    • 010 = ~11.7 microseconds
    • 011 = ~16.0 microseconds
    • 100 = ~20.2 microseconds
    • 101 = ~24.5 microseconds
    • 110 = ~28.8 microseconds
    • 111 = ~33.0 microseconds
  • Bits 5-7 contorl the amount of time when port 20 contains 3. The following values tell the amount of time.
    • 000 = ~3.2 microseconds
    • 001 = ~7.4 microseconds
    • 010 = ~11.7 microseconds
    • 011 = ~16.0 microseconds
    • 100 = ~20.2 microseconds
    • 101 = ~24.5 microseconds
    • 110 = ~28.8 microseconds
    • 111 = ~33.0 microseconds


Comments

This value really shouldn't be changed. TI-OS depends on this being set high enough to function for the LCD delay.

Also the 83+SE has this port set to 4A as defualt, the 84+(SE) has this port set to 4B as defualt.


Credits and Contributions

  • James Montelongo
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