Aucbvax.2883
fa.unix-wizards
utzoo!decvax!ucbvax!unix-wizards
Tue Sep 1 02:12:45 1981
>From SomeoneOnUUCP@Berkeley Tue Sep 1 02:07:02 1981
Originating from cincy at Wed Aug 19 17:08:08 1981
We have a Ramtek 9200 on our 11/60. It gives us no end of trouble.
I believe you would have the same type of interface -- half
dr11b, half dr11c, right? (They call it a GPIF interface.)
We tend to warn people off the machine when someone wants
to use it, because more often than not, it will hang the
bus within a few moments. I redid the driver a few months
ago to do DMA out of the user's buffer, and that caused me
more trouble -- at that speed the bus contention is too much
to run it in 'burst mode', that is, it only arbitrates once
for the bus transfer. We now run it so it arbitrates on every
word (yuck!). But at least it doesn't foul swaps as it used to.
I really don't like the device at all, because it is so dumb
in how it handles the bus. If anything is wrong (if it gets
confused) it won't just set an error bit; rather it hangs the
UNIBUS. I would suggest to you that if you can run it in a
slow DMA mode, you will probably have more luck.
Chris Kent
(pur-ee!purdue!cak)
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