Quoting Ignatios Souvatzis (14-May-00 21:43:20):

> Maybe I should have been more elaborate... 

> as sync transfers don't work reliably with either AmigaOS or
> NetBSD..., I suspect the drivers are not faulty.

> (sync transfers can be MUCH faster, especially with UW boards like
> the CSPPC, than async transfers, making correct high frequency
> behaviour of the cable 
> (which includes termination) and correct timing behaviour of the
> disk firmware and the drivers VERY important.)

> Now, I guess this doesn't help you much, especially as you're
> convinced that your cables and termination are correct... 

Well, I believe everything is fine, sync works fine with the Viking
until I start to backup the drive to the streamer. Hangs occu quite
frequently. While setting up the CSPPC UW SCSI, I got pretty deep into
this termination business. To the very best of my knowledge, it's all
right. However I have some timig problems with my Amiga 3000 since I
got the CSPPC. The hangs could possibly be related to this problem,
but I rather doubt that. These timing problems show also up while
backing up the viking (even with async). Ther result is 1-2 longword
compare errors with 3.8 GB backup! The CSPPC screws up the entire
machine timing! It's a known problem with p5 products and A3000s
(possibly also other Amigas).

> Let me explain how to force the siop2 driver to avoid sync transfers
> even if the disk claims it can do them. (I had to look up driver
> source to make sure this works with this driver, which is why I
> didn't mention it earlier).

Ok.

> the boot block (and loadbsd) take an option "-I somenumber", where
> number is a 32 bit number used to pass sync inhibit flags to some
> scsi bus drivers.

> sbic (A3000 internal) and siop and siop2 are aware of this.
> sbic (which is scsibus0, so it comes first) uses up 8 bits of this
> (from the right). siop2 will be scsibus1, and it consumes 16 bits,
> each denoting one target id
> (wide scsi has 16 of them) which won't be asked for sync transfers.

Ok.

> so booting with 

> netbsd (other parameters) -I 0xffff00 will inhibit sync transfers on
>  all siop2 targets. Please try this.

While booting up with -I 0xffff00, NetBSD is able to take the *.tgz
files from the viking (which is connected to the CSPPC SCSI). So this
really seems to work!

I have the impression (not sure at all!) that my final external
device, the HP 6200C scanner doesn't terminate properly (=actively?).
The docs say it is supposed to terminate actively, but I'm not sure at
all.

At least, we do know now that it works with sync off.

> This is more or less explained in "man 8 boot". I understand it is
> difficult to read without a running system.

That's right.
Thanks for your understanding! ;))

TIA

-- 
Cu  Georges Heinesch, Luxembourg
    geohei@geohei.lu
    http://www.geohei.lu
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