> To: Sonnet Technical Support
> attn: Mike J. Wong
>       Hardware/Software QA Analyst
> 
> Dear Mr. Wong,
>      As an owner of a Sonnet Crescendo G3/L2 card (the 240Mhz one), I have
> contacted you before about my concern that the card or the extension do not
> turn off speculative addressing, while other manufacturers do this. I still
> have occasional crashes and boot crashes which I can only trace back to the G3
> card. Now on 2 sites your competitors have engaged in a discussion about the
> speculative addressing issue. While they do not agree about the solution
> (hardware or software disabling), both are very adamant that on older Macs one
> should disable speculative addressing. Do you to the contrary still claim that
> this is not the case. Here are the links for the discussion:
> http://www.powerlogix.com/support/spec.html
> http://macspeedzone.com/articles/theperformanceedge/newer/speculativeprocessin
> g.html
> http://www.macspeedzone.com/frames/performanceedge.html
> 
> E.g. NewerTech states:
> ---- begin quote ----
> However, speculative processing cannot be allowed when accessing non-memory
> devices such as system resources. Devastating problems could occur if
> speculative processing is allowed when accessing the hard drive controller,
> sound generator, video, Ethernet, serial, USB, keyboard, mouse, etc. 
> 
> Because the speculative processing problem is due to improper access to any
> hardware which
> controls In/Out functions, almost any symptom is possible. Also, minor system
> configuration
> changes can mask or reveal the problem. Some of the symptoms, and there are
> many, include
> almost any standard Macintosh function such as:
> 
>                      Occasional unexplained crashing 
>                      Slow Ethernet connection 
>                      Chime at boot but no video 
>                      Corrupted video, artifacts on monitor 
>                      Hard drive corruption 
>                      Can't find OS on hard drive 
>                      Distorted sound or boot chime 
>                      Problems with PCI cards 
>                      Corrupted backups 
> ---- end quote ---
> 
> I would appreciate it if you could explain in some detail why you do not
> disable it on older Macs upgraded with a G3 card. Previously you stated:
> "Speculative Addressing is left enabled to allow protection for I/O
> addressing". From the discussion on these above pages I conclude that
> speculative addressing can corrupt I/O addressing and disabling it would
> protect the I/O addressing. I am carbon copying my email to two sites so that
> other current (or potential future) Sonnet users are made aware of possible
> differences between your and your competitor products.
> Sincerely,
> Anton


REPLY FROM SONNET---------

The reply I sent you was directly from my lead software engineer. We disable
speculative addressing. 
Christy
Sonnet Technical Support
support@sonnettech.com


>Reply to:  RE: Speculative addressing question for Mike Wong
>Anton,
>
>Mr. Wong is no longer with Sonnet. We Disable speculative addressing for all
>I/O accesses on all of our G3/G4 cards.
>Christy
>Sonnet Technical Support
>support@sonnettech.com