This Amiga 4000D has a secret:-D

[iamaboringperson]

This Amiga 4000D has a secret:-D

But we'll soon find it out! :-)

[mboehmer_e3b]

Ah. I smell a rat... nice to hear something from Elbox again...

The PCI specification does not allow passive PCI expanders!

Not correct. The PCI spec 2.1 says:

"5.2.2.: [Planar implementation] Two types of planar implementation are supported by the PCI expansion card design: ... and expansion connectors mounted on a riser card."

These riser cards are also commonly used in small size systems.

So. Quoting on PCI specs:

"3.7.4.: [Generating configuration cycles]... Configuration mechanism #2 is defined for backward compatibility and must not be used by new designs [footnote 21: This mechanism adds a significant software burden and impacts performance when used in a multiprocessor system]."

Hm. How does Mediator handle this? It uses only the config mechanism #2, which is forbidden according top 2.1 specs for new designs... and what does this mean for SharkPPC cards, which sit behind a bridge (which *needs* mechanism #1, btw)?

So, if quoting, Tjaoz, be fair.

Michael

[redrumloa]

@Crusher

Those are some really nice pics:-)

Just say if you want some more.

Please:-) A picture a little zoomed out showing the whole bottom half of the A3000T would be nice! Thanks!

[Crusher]

No problems, I hope these are satisfying. Sorry for the quality, didn´t get the lights where I wanted.

http://img329.imageshack.us/img329/3088/p7063718ri3.jpg
http://img530.imageshack.us/img530/8000/p7063720hr3.jpg
http://img367.imageshack.us/img367/3135/p7063722cr7.jpg

If these are not what you had in mind then don´t hesitate to ask again. I love taking pictures on my Amiga.  :-D

[tjaoz]

@mboehmer_e3b

Ah. I smell a rat... nice to hear something from Elbox again...

Poor Michael,

You think that anyone who is familiar with electronics is related to Elbox. :-)

Not correct. The PCI spec 2.1 says:

"5.2.2.: [Planar implementation] Two types of planar implementation are supported by the PCI
expansion card design: ... and expansion connectors mounted on a riser card."

These riser cards are also commonly used in small size systems.

The risers mentioned in the PCI spec are only for motherboards designed to use the 'extender' or 'riser' cards. When you have such a motherboard you can treat the 'riser' (extender) card as the part of this motherboard. The point is that such motherboards have shorter signal lengths. In this kind of systems, the sum of the motherboard and 'riser' card clock length is always 2.5".

It is surely not the case of the Prometheus board.

The attempt to install the Voodoo card in the passive expander will cause violation of input setup times for signals driven by the Voodoo card plugged into the extender. It means that reading from the Voodoo card memory will be disturbed. Without reading the Voodoo card memory the dream about any future support for any PCI busmaster card (sound, TV, Fast Ethernet, USB,...)in Prometheus is ended...

So. Quoting on PCI specs:

"3.7.4.: [Generating configuration cycles]... Configuration mechanism #2 is defined for backward
compatibility and must not be used by new designs [footnote 21: This mechanism adds a significant
software burden and impacts performance when used in a multiprocessor system]."

There is not such a statement in the current PCI specification.

Hm. How does Mediator handle this? It uses only the config mechanism #2, which is forbidden according to 2.1 specs for new designs... and what does this mean for SharkPPC cards, which sit behind a bridge (which *needs* mechanism #1, btw)?

Your problem has nothing to do with this tread. Well, apart from the fact that the docs for the Prometheus show that Prometheus does not support config mechanism Type 1, which you named #2.

AFAIK Mediators support both kind of configuration mechanisms described in the PCI spec: Type 0 and Type 1.
But you should rather contact Elbox if you want to learn something more about it.

So, if quoting, Tjaoz, be fair.

I'm fair. It is you who quoted PCI specs parts not related to this thread.

[spirantho]

Just my $0.02c....

tjaoz is quite correct, red's hack is beyond PCI specifications.... the timing constraints are such that trace lengths, particularly like that patch cable, are going way beyond spec.

However, that's not to say that such a system won't work. PCI card manufacturers will allow a certain tolerance otherwise they'd get truckloads of returns, so as with many things of this ilk, YMMV. Some cards will work fine, others won't like it at all, probably... but it's still way better than nothing, especially for A3K owners.

Incidentally, not only do I not work for Elbox, but I'm also the proud owner of a A4K (towered!) Prometheus/Voodoo/RTL8029 set up which works perfectly, and I'd have no hesitation in recommending the Prometheus to anyone.

Congrats to redrumloa - I think you've probably just helped Matay somewhat!

[redrumloa]

@Congrats to redrumloa

Thanks, I appreciate that. Incidentally despite the fact the flex cable setup worked flawlessly, it was only a first attempt and has since been revised. By the end of the week I should be able to post more pictures.

[mboehmer_e3b]

Ah... I smell a Rat again...

There is not such a statement in the current PCI specification.

There is: PCI Specification of PCI SIG Version 2.1s

And that's what Elbox is advertising the Mediator to be compatible with.

AFAIK Mediators support both kind of configuration mechanisms described in the PCI spec: Type 0 and Type 1.

Don't try to confuse people by discussing about numbering.
First one of configuration methods is being routed over PCI-PCI bridges, where as the latter one is limited to one PCI bus segment only (will not be forwarded by PCI bridges).

I'm fair. It is you who quoted PCI specs parts not related to this thread.

You were talking about specification violations. Same for me.

Michael