PCI 5-slot riser card - good for ???

it's got a long PCI (64 bit?) connector and 5 short PCI slots. It uses a DEC 21052 PCI bridge chip.

Numbers on the PCB:
820-0852-A
630-2208
C70
dated 9645
plus a barcoded sticker:
9651 TDII 01-W1612B01A

Found it while digging through boxes of stuff. I expect it's useless except in whichever machine from which it came (C700? PowerCenter Pro? StarMax?), but here's the question - anyone see any danger in plugging it into a Mac LB just to see if somehow it might actually be functional in a 'regular' Mac system?

The obvious idea would be to use it in a Mac to add extra PCI slots. Why? LOL, because, like Mt. Everest, it's there.

dan k

It might be useful for Doug's quest to build a PCI breakout box for the Quadra 950.

I don't know if any Mac clones had 64-bit pci slots. Does it connect to the motherboard through a pci slot itself?

Yeah, you'll probably fry the Mac's PCI controller, if not the entire motherboard. If it were a simple 2-to-1 PCI slot adapter, there wouldn't be any harm really, but the presence of a controller chip means that it's highly proprietary. In fact, I'd be willing to bet that the chip on there is actually the PCI controller.

but not the slots, those are normal shorties (33mHz, 32 bit.) I don't know if that long edge connector is actually a PCI jobby at all, just that it fits into a long slot, like the B+W PCI slots (but not the B+W short 66mHz video card slot.)

Only 64 bit slot Macs I have are B+Ws, hate to toast an otherwise perfectly good MLB fer nuttin'. Anyone else want to chime in before I toss this relic back into the bin?

dan k

page at lowendmac shows the Starmax systems with 3 slots for desktop, 5 for tower. Likely candidate, eh?

Other vendors of similar Tanzania-based 3.3v EDO ram systems included APS and M*Power as well as Apple (Powermac 4400.)

Edit: here's a nice page!

dan k

It sounds like the 64 bit connector might mate with a PDS slot on the mobo if it's not actually a 64 bit PCI slot. Is there another PCI bridge chip on the MLBs mentioned, or is that a function of the main bus controller on PCI Macs?

I wonder if that card could be used to hack PCI slots onto something like a 3400 MLB or to bridge additional slots onto a 6400/6500 MLB?

jt

No, it won't hurt the mac at all. The worst that will happen is the machine won't work. It's a PCI compliant device. If the voltages are incompatible, you won't be able to insert it into the slot.

Also, Apple actually uses a DEC PCI-PCI bridge, so there's actually a small chance it'll actually work.

Cool! Next time I fire up a B+W (which has the 64 bit PCI slots matching this riser) I'll stick it in (without any PCI cards at first) and see if the bridge shows up in the device tree.

I'm not sure if this is a useful 'hack', but curiosity is my middle name.

dan "curiosity " k

Post some pics...