I've used a UNI-Pod and still do. As long as the latest software was installed, it fixed all the filer issues the early stuff had and it's still going strong. It was a few years ago but I did some experimenting and did get the internal 8 bit expansion working with an Econet module, sound sampler and SCSI interface. It was a hack to get the software working but all it took was to change the address offset from the default Econet address to point to the card and a patch to the drivers to fiddle with the IRQ mapping. The podule seems to have multiple IRQ sources and there were registers to enable the expansion FIQ/IRQ to the podule bus. Although it had an FIQ pin, it appeared as just another IRQ. I chose the podule base offset address according to slot number and the podule access cycle needed for the devices on the "econet" modules.
For the sampler and econet, I worked out which pins were connected from the module to the the 15 way back panel connector and wired up a plug to suit. Worked quite nicely. I assume that this is the "parallel port" mentioned in previous comments?
I found my old notes the other day - original hard drive long gone - and the more technically inspired users might find this of interest:
Expansion socket base offset &3A00
A0 of the slot was connected to LA2 of the bus and so on.
status was the masked IRQ = raw AND mask
I worked out that the expansion "FIQ" mask bit was bit 7 and the IRQ mask bit was on bit 1. Bit 0 appeared to be the global podule IRQ. Whenever I played with bit 0 of the IRQmask, bad things happened The other bits appeared to be for the IDE, network and USB. It goes without saying that a read/modify/write was needed with IRQs off to change any of the mask bits.
Back on topic, I for one am looking forward to seeing exactly what's on the new V-POD. If naming is anything like the UNI-Pod (usb, network, ide) then I vote that V is for Video