23 Dec
2013
23 Dec
'13
1:13 p.m.
On 12/23/13 10:05 AM, Ethan Dicks wrote:
This is the opposite
of what IBM did with the PC where *every* PC had a multi-channel
DMA engine that any peripheral could use (floppy, hard disk, sound
card...)
Which has come to bite us in the ass 30 years later when modern systems
can't support legacy peripherals that used those
DMA channels (re. the software compatible floppy interface thread).
The performance of those MB DMA channels were pretty poor, too, along
with the fact that they couldn't be upgraded due to backwards compatibility
and the stupidity of the ISA signaling polarity of DMAs and IRQs
oh.. I forgot about DMA/IRQ conficts.
They did us no favors by having them.