Subject: Re: 2940 & netbsd-current
To: None <>
From: Charles M. Hannum <>
List: current-users
Date: 03/31/1996 15:35:54 (Martin Cracauer) writes:

> Sorry, I didn't get it. Do the Buslogic cards have some kind of
> OS-independent abstraction layer over the hardware?

Well, `OS-independence' isn't really relevant.  The difference is that
the older Adaptec, BusLogic, Future Domain, UltraStor and Western
Digital cards all use an abstraction layer on top of the SCSI
transport layer.

This has the notable advantage that the transport layer can be
completely replaced, e.g. with the fibre channel protocol or the
serial bus protocol in SCSI-3, without the high-level software having
to know the difference.  (In practice, though, I haven't seen any of
the vendors actually produce cards using these protocols that share
the old APIs, so the point has been inadvertantly declared moot.)
Also, in the case of BusLogic, it meant that the entire line of cards,
including EISA and PCI models, could share the same interface.

It has the disadvantage that you're pretty much limited to whatever
they programmed the card to do.  And you can't fix bugs.  (For
example, my BusLogic 542B just locks up if I allow it to start sync
negotiation with a NEC MultiSpin 4x, because it doesn't deal
gracefully with what is arguably a firmware bug on the NEC.  The
likelyhood of BusLogic ever fixing this for me is more or less 0.)

So you win some and you lose some.  *shrug*