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Documentation about the Vampire hardware

Chip RAM In 2023/1 Core

Manfred Bergmann

Posts 235
20 May 2023 10:01

Hello.

I noticed (on Icedrake) that the Chip RAM is around 6MB in these cores (9234) which I didn't recognize before.
Is this a new feature?

Manfred


Gunnar von Boehn
(Apollo Team Member)
Posts 6258
20 May 2023 13:29

Manfred Bergmann wrote:

  Hello.
   
    I noticed (on Icedrake) that the Chip RAM is around 6MB in these cores (9234) which I didn't recognize before.
    Is this a new feature?
   
   
    Manfred
 

 
Hallo Manfred,
 
with the V4 Accelerators you have the choice to run them on 2 modes.
 
1) Only Accelerator mode.
In this mode the Accelerator give you the CPU, the FPU, the Fastmemory, the extra IDE controller (this means system with IDE already like A600 and A1200 have then 2 IDE controller that you can use in parallel), the USB, and the Ethernet controller, the 3D accelerator and the 16bit audio.
 
2) Super-AGA upgrade mode.
If you select this mode then you get all the above, plus
you get in addition 6 MB Chipmememory upgrade and the ability to play AGA games - even on A500/A600 systems
 
 
These two modes are also explained in the recent Manual.
And how to select them with a jumper. :-)


Manfred Bergmann

Posts 235
20 May 2023 14:55

OK, thanks.


Bartos Lisowski

Posts 20
26 Jul 2023 15:41

Thanks for the Explenation :)


Amiga 4Life

Posts 105
28 Jul 2023 12:47

ok so we get to operate chipram in 1 of 2 modes, "motherboard chipram" or "accelerator chipram". I haven't tried it yet, but does anybody know if the Firebird is compatible with 2mb chipram expanders, (for example Dkb's MegAChip 2000/500).... .. (there are some accelerator cards that are not compatible with this chipram upgrade, and this is with A2k)....


Amiga 4Life

Posts 105
28 Jul 2023 12:56

@gunnar
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 :)   


Gunnar von Boehn
(Apollo Team Member)
Posts 6258
29 Jul 2023 09:12

Amiga 4Life wrote:

@gunnar
  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:


Address
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.


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