It should be noted that there's plenty of multi-I/O cards where the FDC can be set to the secondary address, ie. 370h.
But they don't allow to change the IRQ nor DMA.
In theory, that shouldn't be a problem if one's not using both FDCs simultaneously.
In practice... the cards I tried just wouldn't cooperate...
Hopefully AHA-1542CF properly handles IRQ and DMA sharing.
If not, then there's the last resort: AHA-1542B, where it's possible to set the secondary address AND secondary IRQ AND secondary DMA.
So, hardware-wise it's 100% sure to work, but I don't know about software...
Anyway, to anyone who manages to get two FDCs working together:
Please precisely describe your config...
- what's the primary FDC
- address, IRQ, DMA of the primary
- capacities of the drives connected to the primary
- what's the secondary FDC
- address, IRQ, DMA of the secondary
- capacities of the drives connected to the secondary
- CONFIG.SYS/AUTOEXEC.BAT drivers
- are all the drives available in DOS as regular drive letters?
- are all the drives available via BIOS calls, for software like DSKIMAGE ?
- are all the drives available in popular software that accesses the FDC directly, like DISKDUPE ?