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

Revision as of 04:23, 7 April 2015

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.
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.

SafeRAM Areas:

D031F6 - pixelShadow
D052C6 - pixelShadow2
- These locations are rarely used by the OS, especially pixelShadow2. Each is 8400 bytes in length; and since they are linear, provide a total free space of 16800 bytes of RAM.

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

@@ Line 9: / Line 9: @@
 * D40000h: Start of VRAM. 320x240x2 bytes = 153600 bytes.
+SafeRAM Areas:
+* D031F6 - pixelShadow
+* D052C6 - pixelShadow2
+** These locations are rarely used by the OS, especially pixelShadow2. Each is 8400 bytes in length; and since they are linear, provide a total free space of 16800 bytes of RAM.
 [[Category:84PCE:RAM|RAM Areas by Address]]