Difference between revisions of "Category:84PCE:RAM:By Address"

From WikiTI
Jump to: navigation, search
(Updated language, added MMIO note)
Line 13: Line 13:
  
 
SafeRAM Areas:
 
SafeRAM Areas:
* D031F6h: pixelShadow
+
* D031F6h: pixelShadow - 8400 bytes
* D052C6h: pixelShadow2
+
* D052C6h: pixelShadow2 - 8400 bytes
* D07396h: cmdPixelShadow  
+
* D07396h: cmdPixelShadow - 8400 bytes
** Each is 8400 bytes in length; and since they are contiguous, provide a total free space of 25200 bytes of RAM.
+
* D09466h: plotSScreen - 21945 bytes
 +
* D0EA1Fh: saveSScreen - 21945 bytes
 +
** Note that the above is contiguous, which provides a total linear free space of 69090 bytes of RAM.
 
** pixelShadow2 is the most stable; and is a viable option for testing TSRs and hooks.
 
** pixelShadow2 is the most stable; and is a viable option for testing TSRs and hooks.
 
[[Category:84PCE:RAM|RAM Areas by Address]]
 
[[Category:84PCE:RAM|RAM Areas by Address]]

Revision as of 11:02, 4 May 2015

See also list of RAM areas by name.

Please read our page on Contributing before editing these pages!

The eZ80 has a 24-bit linear address space. Layout:

  • 000000h: Start of flash. The first 128 K are locked boot sectors. The first 8 are divided into 8 K sectors, all of which are locked. The certificate is now a single 64 K sector, so I hope you don't crash while rebuilding it.
  • 000066h: Flash exception handler. Write-to-flash without permission triggers the non-maskable interrupt to fire.
  • 00007Eh: Hardware/Emu flag: This byte indicates whether the ROM is a hardware ROM or emulator.
  • 000080h: Start of boot code jump table.
  • D00000h: Start of RAM. 256 K.
  • D40000h: Start of VRAM. 320x240x2 bytes = 153600 bytes.
  • E00000h: Start of memory-mapped I/O address spaces.

SafeRAM Areas:

  • D031F6h: pixelShadow - 8400 bytes
  • D052C6h: pixelShadow2 - 8400 bytes
  • D07396h: cmdPixelShadow - 8400 bytes
  • D09466h: plotSScreen - 21945 bytes
  • D0EA1Fh: saveSScreen - 21945 bytes
    • Note that the above is contiguous, which provides a total linear free space of 69090 bytes of RAM.
    • pixelShadow2 is the most stable; and is a viable option for testing TSRs and hooks.