Graphics card memory->Amiga fast ram?

[manicx]

Can I assign part of the Cybervision64's 4 Megs to be used by the Amiga as fast ram? Is this safe for the graphics card? How about performance of the Cybervision 64?...

[Jope]

No-one's done that as far as I know..

If you know how your RTG software allocates the memory, then you might be able to add the unused memory to the mem pool..

Then again, I think both CGX and P96 use the entire ram for storing screens..

Anyway, it'd be Zorro III RAM at best - much slower than what's on the CPU card.

[thomas]

I saw a program on Aminet that could configure part of the graphics memory as fast mem. But why ? People have 32 MB or more fastmem nowadays and the graphics card needs its memory to reach a reasonable resolution (1024x768x16 = 1.5MB, for one display only, invisible bitmaps not counted).

[manicx]

I need this because I can't find a cheap cyberstorm or any other accelerator for my A4k. I cannot affor spending lots of money for a new accelerator but I already have 2*32 MB simms (just need the board). Therefore, I am stuck with 16 MB fast and 2 MB chip. I've made a basic installation of OS3.5 and I have 2 MB Chip and 14 MB Fast free. So I want to compensate for the loss of the 2 MB for the OS! I am counting every single Kb here FFS!!!

[Severin]

forget it, it only worked with the old frame-buffer type cards that were only used for the odd picture or anim playback... most of the time they sat there doing nothing, unlike your cv64 that doesn't have any off time...

if you open 2 screens larger than 800x600x8 at the same time you will lose even more fast ram as one screen will be buffered in fast ram

best you can do for now is limit memory usage... eg. 800x600x8 WB, don't use Dopus 5+ as wb replacement, patterns instead of pics for wb backdrops, run as much on WB as you can etc...

you might be able to find an old ZII 8 mb ram card, they're really cheap (5 to 15 quid)... I'm not sure if they work with A4000's, but should, iirc they map the memory to 0x20000 which is not part of the main memory area on a 4000...

[ant512]

There *is* an Aminet patch that lets you use CV64 memory as fast RAM:

http://wuarchive.wustl.edu/~aminet/g.../AddCybMem.lha

From the readme:

`AddCyberMem' adds a user-specified amount of memory from the end of the CyberVision64's on-board display memory to the exec list of free memory - you can use it as if it were standard FAST memory. By default, it gets Priority 10, so the real FAST memory is preferred, but not the CHIP memory.

However, this has inherent problems, the major one being the speed of the CV64's RAM - it'll slow your system down.

As Severin says, the best solution is to get rid of the rubbish from the OS that you don't need. And then, get rid of the OS - replace the bloated 3.5 release with the standard 3.1 Workbench. It'll boot with less than half a meg of RAM used.

[FromWithin]

Originally posted by ant512
However, this has inherent problems, the major one being the speed of the CV64's RAM - it'll slow your system down.

Bah. You'd hardly notice that. I used to use my Amiga 1200 with a 4MB PCMCIA exapansipon card, and it was fine. That was supposed to be the slowest RAM you could get.

Use the patch. It's fine.

[manicx]

Thanks everyone. I will give a shot with AddCybMem (BTW this is the tool I was taking about, I just didn't remember its name)... Just one question:

Prior of installing O.S 3.5, I was using a heavily modified 3.1. It sucked! It was unstable and runty! After installing OS 3.5, my WB is stable (not to mention that visiually, it's lovely. I only miss 2 Megs of memory and I don't have to look at the ungly 3.1 icons. So, why should I go back to 3.1? No way! You may install patches and other stuff in 3.1 and still use less memory that OS 3.5, but it's sooooooooooooo unstable after!

[ant512]

Originally posted by FromWithin
Bah. You'd hardly notice that. I used to use my Amiga 1200 with a 4MB PCMCIA exapansipon card, and it was fine. That was supposed to be the slowest RAM you could get.

Use the patch. It's fine.

You wouldn't notice any problems using slow 16-bit RAM if you've never used a proper RAM expansion. The A1200's chip RAM was either 16-bit or 8-bit, depending on what Commodore could find when they were making a batch of machines, so there's no real speed difference between PCMCIA RAM and chip RAM. However, adding a 32-bit trapdoor expansion doubles the speed of an A1200.

If you were to insert the PCMCIA RAM into a machine with a trapdoor upgrade, the computer's speed would drop, probably down to its original level.

As for stability, I use DirOpus Magellan 2 with very few patches, so that's not really an issue. The system does use 8MB of RAM and take as long to boot as WinXP, though...

[FromWithin]

Originally posted by ant512
If you were to insert the PCMCIA RAM into a machine with a trapdoor upgrade, the computer's speed would drop, probably down to its original level.

I had a GVP board with an 030 and 8MB as well. The mem priority on the PCMCIA card was set to lowest so it only accessed it when it was totally out of RAM (It actually used to dip in there quite often).