|Amiga 4Life wrote:
How come we're not seeing the 8mb chipram, the A4k has the jumper for 2MB/8MB chipram option...(or is that reserved for the Kraken :)
Let me explain the options.
The 68000 CPU has 32bit register but of the 32 only 24 address wires are put outside of the chip.
With 24 Address lines you can address 16 MB maximum.
In this 16 MB address space the Amiga has several spot already placed.
Let me show you the address layout:
0/1 2 MB Chipmem space
2/3/4/5/6/7/8/9 8 MB ZorroII space / Can also be used as Chipmem
A/ B(1st halve) 1.5 MB space could be used as Chipmem
B 2nd halve 0.5 MB CIA SPACE
C and D(1st halve) 1.5 MB Ranger Memory Expansion
D (2nd halve) 0.5 Chip Registers / IDE
E/F 2 MB ROM space
All the V4 Accelerators have build in
* Ranger Memory expansion (1.5 MB)
This is great for game compatibility as many old games use it.
The V4 accelerators allow you to use
2 MB chipmem + the first 4 MB of the ZorroII space as Chipmem.
This gives you a total of 6 MB and leaves you 4 MB free expansion space. This space you can use on the A600/A1200 using the PCMCIA,
and on the A1000/A500/A2000 using Zorro cards.
If you not have any cards that you want to plug into your Amiga ... then this memory could be used as Chipmem too.