On Wed, Jan 31, 2007 at 08:20:40PM -0500, Michael Lorenz wrote:
> Well, some other archs do the same, namely shark and prep, I'm pretty 
> sure there are more, so it's not that much of a curiosity.

Well, it's a curiosity if you're expecting splhigh to block everything.

> Stupid question - why wouldn't we want DMA at least for sending?

It might be OK, but for the console, I generally want things to be
pretty much dead simple so that I know they'll work with all interrupts
blocked for DDB or KGDB access.

> Z80 SIO programming some time before the previous ice age - if the mac 
> serials aren't too retarded compared to the Z80 SIO they should support 

I don't recall what Z80 systems used for SIO.  The macs use either
a real Z8530 or an ASIC core that should be bug-compatible.

-allen

-- 
Allen Briggs  |  http://www.ninthwonder.com/~briggs/  |  briggs@ninthwonder.com