More than 128 mB on a CSPPC?

[jack-3d]

I believe the biggest problem with more ram on a CSPPC or MKIII is the fast slot on A3000 and A4000 can only address 128mb of ram.  I don't think there are physically more address lines that can be used to allow the A3000/A4000 to access more than 128MB even with 060 on the CPU card.

I specifically asked about 128 MB limit for fast cpu on Apollo core forum and Biggun answered there is no such limit as they plan way more ram for big box Vampire. So I suppose the limit is made by phase5 on their cards.

[omnicron10]

There might not be a limit if you patch exec or other functions like they had to do with the Vampire 2 on the A600 (and A500 I believe).

It was stated on http://www.apollo-core.com/knowledge.php?b=5¬e=2047&x=1&z=L4DAbc that there is no physical limit.  What exactly that means is not clear.  Software or electrical is still possible.

[QuikSanz]

There might not be a limit if you patch exec or other functions like they had to do with the Vampire 2 on the A600 (and A500 I believe).

It was stated on http://www.apollo-core.com/knowledge.php?b=5¬e=2047&x=1&z=L4DAbc that there is no physical limit.  What exactly that means is not clear.  Software or electrical is still possible.

Interesting thread over there. With the speed of that bus and really fast memory I would be very surprised if you could fill .5Gig.

[psxphill]

I believe the biggest problem with more ram on a CSPPC or MKIII is the fast slot on A3000 and A4000 can only address 128mb of ram.  I don't think there are physically more address lines that can be used to allow the A3000/A4000 to access more than 128MB even with 060 on the CPU card.

According to this, the slot has all address lines.

http://www.thule.no/haynie/systems/amiga3k/docs/a3kcpu.pdf

Local bus slot memory doesn't use autoconfig and only 128mb was reserved, however I'm sure it would have been possible to have worked round that if that hadn't seemed like a ridiculous amount of memory when the cpu cards were designed. If I were designing an accelerator today then I'd have 4gb of ram soldered to it and then have the rom on the cpu card wait until everything else had been autoconfig'ed and then map all the unused address space as ram.

[omnicron10]

According to this, the slot has all address lines.

http://www.thule.no/haynie/systems/amiga3k/docs/a3kcpu.pdf

Local bus slot memory doesn't use autoconfig and only 128mb was reserved, however I'm sure it would have been possible to have worked round that if that hadn't seemed like a ridiculous amount of memory when the cpu cards were designed. If I were designing an accelerator today then I'd have 4gb of ram soldered to it and then have the rom on the cpu card wait until everything else had been autoconfig'ed and then map all the unused address space as ram.

Good find on the PDF. I remember seeing that before.  I was looking for it again.  The fast slot looks like it is just and extension of the 030 bus.  I still think patching the KS will be needed to support more than 128mb of ram on that bus.  From reading posts on the zorram and DKB and other large Z3 memeory expansions, there are a lot of bugs in expansion.library that will require fixing to make things happen easily.

[jack-3d]

@ jack-3d
Try to load 2 or 3 jpeg photos (each of a size of roughly 12 mB) into ArtEffect (enough virtual Ram enabled), while there are other programs (like Wildfire 7 PPC, SnapShoter and Fantastic Dreams) working in the background, and watch the available RAM disappear...
 :-(

Aside from the applications themselves, a lot of ram is consumed by the graphics you load.

As long as you use photos (each with a size of not larger than - lets say - 3 or 4 mB), all works well.
When I have just the OS and e.g. ArtEffect running and load a jpg-photo of just 4mB, ArtEffect 'unpacks' the jpg and makes roughly 70 mB of it in its working memory...

But we're living in a time where digital cameras are very high-res and one single hi-res photo can easily have a size of 12 mB...

Due to ArtEffect's internal structure already loading one single of such big hi-res photos can eat up all the FastRAM on a CSPPC...not to mention having two of them in memory for certain special effects...

Correct, the ArtEffect could be the one, that is able to eat all your ram within seconds. But doesnt this support swap file on your disk drive? CSPPC/MK3 has SCSI3 controller and my disk runs slightly over 30 MB/s. The 68k RAM read/write speed is about 40 MB/s so its not so big difference.

I would be happy to have 512 MB FAST RAM of course, but I dont consider ZORRAM as "fast" and works only as placebo. Lets wait for Vampire A3/4000, we should finally get more then 128 FAAAST RAM.

[psxphill]

I still think patching the KS will be needed to support more than 128mb of ram on that bus.  From reading posts on the zorram and DKB and other large Z3 memeory expansions, there are a lot of bugs in expansion.library that will require fixing to make things happen easily.

expansion.library wouldn't be necessary as I don't think you can autoconfig from the local bus, a resident module in rom that adds memory to exec directly would probably do it. Or you could add the extra memory in a command called from user-startup.