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3.57 em_use

Function

Prepare an extended memory page for use.

Header

em.h

Declaration

void* __fastcall__ em_use (unsigned page);

Description

The function maps one page of extended memory into linear memory and returns a pointer to the page frame. This function is similar to em_map, but will not transfer data into the actual memory window in the assumption that the existing data is wrong or will get overwritten.

Limits

  • Calling em_use will invalidate the memory window, so if you made any changes to the data in the window, call em_commit first, or the changes are lost.
  • The function is only available as fastcall function, so it may only be used in presence of a prototype.
  • The function produces undefined results if no extended memory driver is loaded.

Availability

cc65

See also

em_commit, em_load_driver, em_map

Example

None.


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