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Re: write alignment matters?

On Tue, Jun 21, 2011 at 12:03:10PM -0400, der Mouse wrote:
> Actually, I got the machine from a friend-of-a-friend who was a pretty
> hardcore SCSI geek in a former life (he now repairs organs, the musical
> kind).  He would probably be the right person to ask about this; it's
> not totally implausible he might even have source to the firmware (I
> doubt he could release it to me if so, but he could look at it).

It's a 53c8xx:  we load the "firmware" into it from our own driver.  But
it may have hardware restrictions we mismanage.  Assuredly we've had
that problem before.

Count your blessings at least it's not a 53c810 (siop).  That chip holds
its own program in host RAM, so you have to contend with the whole usual
set of DMA synchronization issues twice over.  The 53c8[2679]x (esiop)
have local RAM for the sequencer program; otherwise they're much the same
as everything back to the 53c700, but that single change makes a big
reliability and performance difference.

Thor Lancelot Simon                          
  "All of my opinions are consistent, but I cannot present them all
   at once."    -Jean-Jacques Rousseau, On The Social Contract

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