mini-pci/pcmcia to PCI bridging

[imported_DrFreeze]

hi guys, i got an idea while browsing my fav webshop, basicly i was thinking if it would be possible to extract the DVD drive from my laptop (old asus A2H) and mod that to an external drive, and use the freed up room to house a PCI vga card

the main idea would be to connect the pci vga card (i found a pci 6200) to the laptop via either the pcmcia slot, or preferably the mini pci slot, and also hook the outputs up to the LCD screen (another matter)

do you guys think this is feasable? i think i could accomodate a low profile PCI card in the DVD bay and even provide sufficient cooling

ive googled the matter already, but the closest thing i can find are some companys offering external PCI card enclosures which connect via pcmcia, im looking to keep my idea internal, and if possible with as little bridge logic (if possible none at all) possible, also it seems im the first person to actually consider this route of upgrading a laptop

so, any thoughts?

(i posted this is HT because i think this level of electronics belongs here, if a mod/admin thinks otherwise, feel free to move this to a more apropriate forum)

 

[hutch1ns]

Good question. I'll have to do some research because this interests me also. Have you looked into how companies like alienware do it? I know they have 7900's and also 7900 SLI cards in their gaming laptops. I've got my dvd drive also pulled out of one of my laptops (along with everything else lol) and was trying to think of a way to upgrade the video also.

If you could keep the topic updated if you find any further info I'd appreciate it. I'll try to do the same.

 

[imported_DrFreeze]

alienware and most recent upgradeable video cards are MXM, a mobile PCI-e standard, specificly designed for this purpose

as a kicker, AFAIK all AGP cards initialise as PCI bus slaves, and then if possible switch up to AGP rates, so basicly every AGP card should be able to run on a PCI bus (thats why pci vid cards dont need a bridge chip, and why those AGR slots on some of the first pci-e mobos were easily made) so theoreticly one could even run a AGP card in a laptop this way

but noone has any technical insight in this?


Hutch, if you could your laptop gutted, could you check how much space you have? after looking at some pics of pci vid card i realize a DVD bay might not be long enough for a vid card

 

[Peter]

Cardbus is technically PCI, and I have seen a Cardbus-PCI expansion chassis once. Problem is, PCI-to-PCI bridging in Cardbus slot commonly isn't well handled, mainly because Windows cannot handle hot-plugging of entire PCI segments, only single devices. (Even if the card is inserted at boot, Windows will have to enable it just like it was hot plugged.)

If you want to hack something directly into the notebook, then yes, it'll work from Cardbus slot or MiniPCI site. Good luck in getting the electrickery right, and also in finding the required thermal attachment.

In other words, get a new laptop.

 

[imported_DrFreeze]

yeah i know a new lappy is far easier, i was just wondering how feasable this idea is

 

[Peter]

Technically you could have a VGA chip on a Cardbus interface, but you won't get boot output from it - it'll work only after the OS has fired up the cardbus hotplugging. BIOS won't do that for you.

On MiniPCI, you are directly on a regular PCI interface, so this is where a fully functional primary VGA replacement could be going.

 

[imported_DrFreeze]

yeah, mini pci was more interesting from the start, i use the pcmcia slot for a wlan adapter already

if only i could make a custom vga board... i dont think even a low profile board will fit, due to length

 

[tex1138]

This is probably more spendy than what you're looking for, but at least you can feast on some eye candy:

http://www.mobl.com/expansion/products/cardbus_expansion/index.html

Sadly, they are very temperamental. It's kind of a crapshoot as to how well they work, and in particular, if your laptop uses a Ricoh CardBus controller IC, forget about it, it tends to lock up the PC. Probably an errata in the Ricoh chip, but Ricoh won't play nice and help track it down, so the problem remained as of the last time I used one of these.

 

[Peter]

That's the one I was talking about. The main problem, as I said, is that current operating systems aren't really capable of setting up a hot plugged PCI-to-PCI bridge - which is what you got with this.
Vista is advertized to change that, results in Linux are mixed.

 

[cheesehead]

Holy zarking fardwarks, that's expensive.
I'll wait for ExpressCard, thank you very much.

 

[Peter]

ExpressCard has one big advantage over Cardbus: There is no "special" bridge chip at the interface point, just a generic PCIE port. This means that BIOS gets to see and initialize the device in the slot - and if that device is a bridge, everything behind it as well.
Things like that extender box will work a lot better from ExpressCard, even if your OS of choice cannot properly reprogram bridges.