This is what I picked up from Elbox while trying to get a Voodoo5 running alongside a PIV under an Apollo 1260 accelerator. I'm no expert, so if I'm wrong with anything, I'll appologise now.
The MediatorZ4 will be recognised as a Zorro board in the Early Boot Screen, but no attached PCI devices will be recognised. The EBS will only show the Z4 bus, the MediatorZ4, any attached Zorro cards and any trapdoor type accelerator.
The Apollo card shows as: 'X'(Device Number) 8738 35 Working (W)
With the Z4 bus in place, its Config Jumpers affect the way attached boards are detected. So, if CFG-0 is Closed, it tells the Z4 to configure the accelerator card as the first config device. It then checks for any ZIII and ZII cards (eg: the Mediator). If no accelerator is present, the Z4 bus will not check its Zorro slots at all.
So, CFG-0 is usually closed with an Apollo is present.This jumper is only opened for diagnostic work.
Installing a MediatorZ4 bus adds further config variables. These are Memory Window jumpers, which allocate areas of memory to different cards. In the EBS, the MediatorZ4 is seen as device reference 2206. This is the only listing seen (apart from the accelerator) if the Med Mem jumper is set to 0Mb.
With the Mem jumper set to 4Mb-Lo you will see:
X 2206 31 W
X 2206 159 W (This is the available PCI memory - no PCI devices are reported)
With 4Mb-Hi See same as 0Mb
With 8Mb See same as 4Mb-Lo
The only other devices reported in the EBS will be Zorro cards. Eg: There are three 2167 modules associated with a Picasso IV. A Prelude card will be reported as 16945
Overclocking the Apollo may affect booting of peripherals on the Mediator.
None of this may solve your issues, but it helps to know what the EBS is telling you.
Cheers,
JaX
