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

Revision as of 11:38, 7 April 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
D052C6h: pixelShadow2
D07396h: cmdPixelShadow
- Each is 8400 bytes in length; and since they are contiguous, provide a total free space of 25200 bytes of RAM.
- pixelShadow2 is the most stable; and is a viable option for testing TSRs and hooks.

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

@@ Line 4: / Line 4: @@
 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.
@@ Line 10: / Line 10: @@
 * 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:
@@ Line 15: / Line 16: @@
 * D052C6h: pixelShadow2
 * D07396h: cmdPixelShadow
-** Each is 8400 bytes in length; and since they are linear, provide a total free space of 25200 bytes of RAM.
+** Each is 8400 bytes in length; and since they are contiguous, provide a total free space of 25200 bytes of RAM.
 ** pixelShadow2 is the most stable; and is a viable option for testing TSRs and hooks.
 [[Category:84PCE:RAM|RAM Areas by Address]]