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croupier
18th February 2015, 07:29
Need some advice regarding 8 bit ISA slots....

What is the max number of ISA slots that can be functional in a PC/clone? It depends on the BIOS of an individual machine or is there a 'standard' controller that can handle a certain number of slots?

My issue is....if I have 2 ISA slots and would like to add a 3rd one (using a passive port extender; i.e. to create 2 ports out of one)....will the extra port be recognized/functional or not?

Thanks!

TheCorfiot
18th February 2015, 08:19
The 8bit ISA bus is a non intelligent parallel bus, it doesnt perform any enumeration but relies on you to set each cards individual resourse requirements manually, usually using hardware jumpers, I/O Address, IRQ, DMA etc..
So as long as your PSU and motherboard tracking can handle the extra power loading then the card you describe should work fine.

:)

AndyLandy
18th February 2015, 09:47
The 8bit ISA bus is a non intelligent parallel bus, it doesnt perform any enumeration but relies on you to set each cards individual resourse requirements manually, usually using hardware jumpers, I/O Address, IRQ, DMA etc..
So as long as your PSU and motherboard tracking can handle the extra power loading then the card you describe should work fine.

:)

And, of course, that you have enough spare IRQs/DMA channels etc. In my 'glory' days of running ISA-based PCs, running out of IRQs was a constant source of frustration!

croupier
18th February 2015, 13:21
Thanks!

Now I need to find an ISA port extender...:)