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

Revision as of 15:43, 14 September 2015

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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.

More SafeRAM Areas:

Also, if you do not wish to use the LCD cursor:

The following 38 pages are in this category, out of 38 total.

@@ Line 6: / Line 6: @@
 * 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. 0FFh is a hardware ROM, 000h is an emulated ROM.
+* 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.