Difference between revisions of "83Plus:Ports:29"
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[[Category:83Plus:Ports:By Address|29 - LCD Speed (6 MHz)]] [[Category:83Plus:Ports:By Name|LCD Speed (6 MHz)]] | [[Category:83Plus:Ports:By Address|29 - LCD Speed (6 MHz)]] [[Category:83Plus:Ports:By Name|LCD Speed (6 MHz)]] | ||
| − | {{SE-Only Port| | + | {{SE-Only Port|01}} |
== Synopsis == | == Synopsis == | ||
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'''Function:''' LCD Speed (6 MHz) | '''Function:''' LCD Speed (6 MHz) | ||
| − | This port | + | This port removes the amount of delay needed between accesses to the lcd driver by adding tstates to the following instructions: |
| + | * out (010h),a | ||
| + | * in a,(011h) | ||
| + | * out (011h),a | ||
| − | |||
| − | + | === Usage === | |
| − | + | Bits 0&1 are unknown, but don't seem to directly remove the needed delay. On the 83+SE these are reset, on the 84+(SE) these are set. | |
| − | + | Bits 2-7 control the amount of delay added at specified instructions. To calculate the tstates added divide the contents of port 29 by 4 and round off. | |
| − | |||
| − | + | == Comments == | |
| + | This port is not available on the normal TI-83+. On the normal TI-83+ this port is a shadow of [[83Plus:Ports:01|Port 01h]]. | ||
| − | + | Bits 0&1 seem to tie to port 2E, they affect the cpu speed reduction the port 2e contorls. Though their exact purpose is not known. | |
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== Credits and Contributions == | == Credits and Contributions == | ||
* '''Michael Vincent:''' Documentation as found [http://michaelv.org/programs/calcs/ports/port29.html here]. | * '''Michael Vincent:''' Documentation as found [http://michaelv.org/programs/calcs/ports/port29.html here]. | ||
| + | * '''James Montelongo:''' Documentation found at [http://www.geocities.com/jimm09876/calc/port29.html here]. | ||
Revision as of 21:39, 22 July 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 01. |
Synopsis
Port Number: 29h
Function: LCD Speed (6 MHz)
This port removes the amount of delay needed between accesses to the lcd driver by adding tstates to the following instructions:
- out (010h),a
- in a,(011h)
- out (011h),a
Usage
Bits 0&1 are unknown, but don't seem to directly remove the needed delay. On the 83+SE these are reset, on the 84+(SE) these are set.
Bits 2-7 control the amount of delay added at specified instructions. To calculate the tstates added divide the contents of port 29 by 4 and round off.
Comments
This port is not available on the normal TI-83+. On the normal TI-83+ this port is a shadow of Port 01h.
Bits 0&1 seem to tie to port 2E, they affect the cpu speed reduction the port 2e contorls. Though their exact purpose is not known.
