🚀 go-pugleaf

>   I never put together that VL cards lock up the local bus to do
> their transfers, whereas DMA transfers to/from an ISA card DON'T!!
> Is this
 
I don't totally get this either.  If one of your peripherals 
on an ISA bus is doing a DMA transfer, what is CPU going to do 
anyways?  I could probably talk to another peripheral but I 
don't see it talking with the memory because of the DMA 
transfer?  And as far as I know, ISA doesn't support 
multi-plexing.  Other than that the only thing I can imagine 
the CPU doing is working from it's RAM cache.
 
Now, what's to stop the CPU from talking to it's cache or 
another peripheral on the bus while a VL-BUS is doing a DMA 
transfer?

I'm assuming we're all using pre-emptive, multi-thread, multi-tasking
os' of course.