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

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The eZ80 has a 24-bit linear address space. Layout:
 
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. Implies that there is no longer a certificate.
+
* 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.
 
* D00000h: Start of RAM. 256 K.
 +
* D1A87Eh: Top of the SPL stack.
 +
* D1A881h: Start of UserMem.
 
* D40000h: Start of VRAM. 320x240x2 bytes = 153600 bytes.
 
* D40000h: Start of VRAM. 320x240x2 bytes = 153600 bytes.
 +
* E00000h: Start of memory-mapped I/O address spaces.
  
 +
SafeRAM Areas:
 +
* D031F6h: [[84PCE:RAM:D031F6|pixelShadow]] - 8400 bytes
 +
* D052C6h: [[84PCE:RAM:D052C6|pixelShadow2]] - 8400 bytes
 +
* D07396h: [[84PCE:RAM:D07396|cmdPixelShadow]] - 8400 bytes
 +
* D09466h: [[84PCE:RAM:D09466|plotSScreen]] - 21945 bytes
 +
* D0EA1Fh: [[84PCE:RAM:D0EA1F|saveSScreen]] - 21945 bytes
 +
** Note that the above is contiguous, which provides a total linear free space of 69090 bytes of RAM.
 +
** [[84PCE:RAM:D052C6|pixelShadow2]] is the most stable; and is a viable option for ''testing'' TSRs and hooks.
  
 +
More SafeRAM Areas:
 +
* D006C0h: [[84PCE:RAM:D006C0|textShadow]] - 260 bytes
 +
* D0232Dh: [[84PCE:RAM:D0232D|cmdShadow]] - 260 bytes
 +
 +
Also, if you do not wish to use the LCD cursor (This is not RAM, but can be used as scrap)
 +
* E30800h: cursorImage - 1024 bytes
 
[[Category:84PCE:RAM|RAM Areas by Name]]
 
[[Category:84PCE:RAM|RAM Areas by Name]]

Latest revision as of 14:02, 31 May 2016

See also list of RAM areas by address.

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.
  • D1A87Eh: Top of the SPL stack.
  • D1A881h: Start of UserMem.
  • 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.

More SafeRAM Areas:

Also, if you do not wish to use the LCD cursor (This is not RAM, but can be used as scrap)

  • E30800h: cursorImage - 1024 bytes
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