> 
> > Hi,
> >    My apologies for possibly sending this to the wrong mail lists (and
> > please
> > inform me of the proper channels;), but I had a question:
> > 
> > 	1)  Does NetBSD-current for i386 support Synchronous and Fast SCSI2
> > 	    operations on the 1542CF?
> 
> I belive so.  These options are largely transparent to the driver, esp.
> Fast SCSI.

They are, if you enable them in the 1542CF setup they will be used.

> > 	2)  Considering the problems in getting specs for the new PCI Adaptec
> > 	    cards, does this mean that there is going to be no further
> > 	    improvement on current EISA and ISA Adaptec drivers?
> 
> I expect so.  Given the availabilty of newer, higher performance stuff,
> I expect that there is enough work there to keep people busy.  The only
> major thing I can see people wanting to get done is the bounce buffer
> support.
> 
> > 	3)  I've heard a lot of people recommend the BT cards.  Can someone
> > 	    tell me more about this card (ie, capabilities, specs, cost, etc)
> > 	    and whether they recommend it over the 1542CF?  Also, if someone
> > 	    can point me to a distributor (I've not been able to locate the
> > 	    cards).  I'm interested in ISA, EISA, and PCI information.
> 
> The VL bus BusLogic is the 445S.  The EISA one is the 747(#?), the PCI
> one is the 946.  The VL/ISA/EISA ones are floppy and SCSI controller.  The
> 946 is SCSI only.  We have several systems with 946S here, combine them
> with some Barracuda's and you get some happening I/O.  I'm planning on 
> getting a 445S for my home system RSN.

A note on the 445S performance, it is not much better than the 1542CF, in
raw drive/controller benchmarking the 1542CF seems to peak about 2.5MB/sec
and the 445S about 2.4MB/sec, this is with a drive that does 4MB/sec on
a 1742.  I am NOT impressed with the performance of *any* VL scsi controllers.
EISA and PCI have them blown out of the water so to speak.

> > 	4)  Can someone tell me about the NCR chipset for PCI SCSI?  Does
> > 	    BT use this set?
> 
> BusLogic (formerly BusTek) uses their own chipsets.  All of their controllers
> are also 1542 compatible, and work fine (and quite a bit faster than the
> 1542) in compatibility mode.  NetBSD has prelimiary support for the 
> NCR PCI chipset, including a PCI bus controller device that should make adding
> other PCI support easier.

Though the controllers are faster than the original 1542 I find them quite
compariable to the 1542CF.  Infact some of the BT cards do not do Fast SCSI
while the equivalent Adaptec card does (ie, bt742).

> > 	5)  The ISA DMA overrun problem found on ISA machines with more
> > 	    than 16 MB of RAM - does NetBSD handle this gracefully, or are
> > 	    files written during this problem corrupted?
> 
> Cards that use the Motherboard DMA controller are okay (currently none, 
> except the floppy drive I think) because that driver has bounce buffers.
> None of the other ones do, although I may hack it for the 1542 driver sometime
> soon.  Bounce buffers are what is used to fix the overrun problem.  If a
> particular I/O is outside of 16M, the system allocates a secodary buffer,
> and copies into it before I/O (on write) or after I/O (on read).
> 
> > Thanks for your help;)
> > 
> > Cheers,
> > Jake
> > jfk@seas.upenn.edu
> 
> BTW...if anyone points you at bounce buffer support for the 1542, let me
> know.
> 
> -Mark
> 
> 


-- 
Rod Grimes                                      rgrimes@gndrsh.aac.dev.com
Accurate Automation Company                   Custom computers for FreeBSD