Difference between revisions of "83Plus:Ports:26"

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'''Port Number:''' 26h
 
'''Port Number:''' 26h
  
'''Function:''' Controls the RAM Execution Upper Limit. See port 25h.
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'''Function:''' Controls the RAM Execution Upper Limit
  
 
This port control the upper limit of RAM execution. It maps the RAM memory space in 1024 byte segments as though it was one continuous address space:
 
This port control the upper limit of RAM execution. It maps the RAM memory space in 1024 byte segments as though it was one continuous address space:

Revision as of 16:02, 28 June 2011

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 03.
This port is protected, which means user programs cannot ordinarily write to it directly.

Synopsis

Port Number: 26h

Function: Controls the RAM Execution Upper Limit

This port control the upper limit of RAM execution. It maps the RAM memory space in 1024 byte segments as though it was one continuous address space:

  • Page 80h: Addresses 000000h to 003FFFh
  • Page 81h: Addresses 004000h to 007FFFh
  • Page 82h: Addresses 008000h to 00BFFFh

etc.

Read Values

  • [00h - FFh]: Multiply the value in this port by 400h to get the highest RAM address that can run code.

Write Values

  • [00h - FFh]: Select a new upper limit.

Comments

This port does not exist on the standard 83 Plus. See ports 5 and 16 instead. Execution of code on addresses above the limit set here will cause a reset.

See Also