Difference between revisions of "83Plus:Ports:28"
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[[Category:83Plus:Ports:By Address|28 - Block Memory Mapping 8000h]] | [[Category:83Plus:Ports:By Address|28 - Block Memory Mapping 8000h]] | ||
[[Category:83Plus:Ports:By Name|Block Memory Mapping 8000h]] | [[Category:83Plus:Ports:By Name|Block Memory Mapping 8000h]] | ||
| − | {{ | + | {{SE-Only Port|00}} |
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== Synopsis == | == Synopsis == | ||
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'''Function:''' Block Memory Mapping 8000h | '''Function:''' Block Memory Mapping 8000h | ||
| − | By an order of 64 bytes per block, this port can re-map data from | + | By an order of 64 bytes per block, this port can re-map data from RAM page 1 to the memory addresses 8000h - BFFFh without regard to the contents of port 7. This port does not map the entire page but only 64 bytes times the value in this port. It maps it starting from low memory (8000h) to high (BFFFh). |
=== Read Values === | === Read Values === | ||
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== Comments == | == Comments == | ||
| − | I can image this port having | + | I can image this port having slightly more purpose than port 27, however it is still unusual. |
| + | calc84maniac says: This port seems to have no effect whatsoever during memory map mode 1, but I may be wrong about that. | ||
| − | + | DrDnar says: I concur. It looks like ports 27 and 28 have no effect in memory mapping mode 1. | |
== Credits and Contributions == | == Credits and Contributions == | ||
* '''James Montelongo''' | * '''James Montelongo''' | ||
| + | |||
| + | == See Also == | ||
| + | * [[83Plus:Ports:27|Port 27]] | ||
Latest revision as of 08:30, 12 March 2013
| 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 00. |
Contents
Synopsis
Port Number: 28h
Function: Block Memory Mapping 8000h
By an order of 64 bytes per block, this port can re-map data from RAM page 1 to the memory addresses 8000h - BFFFh without regard to the contents of port 7. This port does not map the entire page but only 64 bytes times the value in this port. It maps it starting from low memory (8000h) to high (BFFFh).
Read Values
- This port reads the last value written to it.
Write Values
- [00h - FFh]: The value times 64 equals the number of bytes that get re-mapped starting from 8000h. So a vaule of 18h would re-map data in 8000h - 85FFh.
Comments
I can image this port having slightly more purpose than port 27, however it is still unusual.
calc84maniac says: This port seems to have no effect whatsoever during memory map mode 1, but I may be wrong about that.
DrDnar says: I concur. It looks like ports 27 and 28 have no effect in memory mapping mode 1.
Credits and Contributions
- James Montelongo
