Mouse wrote:
Love that term, "bounce buffer" (I wrote a
whole package to support
them in a packet switch I did) - I'm officially adopting it, right
now! :-)
Hey - anything that anyone writes is automatically copyrighted.
I realize you...may have been less than entirely serious. But what you
wrote could easily be taken seriously, especially by someone only
partially inside our culture. So I'm going to be a minor killjoy here.
Yes, anything written now is automatically copyrighted in most
jursidctions. But (a) the term "bounce buffer" is small enough and
obvious enough it probably cannot be copyrighted on its own (and is not
infringing when copied in isolation), (b) was quite possibly published
without copyright claim before automatic copyright and is thus in the
public domain now, and (c) is of uncertain authorship anyway. So...
So first you need permission to use that!
...you actually don't.
Thank you for clarifying that aspect. I just considered
it so ridiculous that anyone would take the joke seriously
that I did not even consider the alternative.
For the case of the RX02 DYX.SYS device driver, the
use of "bounce buffer" was the most descriptive phrase
that I have ever seen. During a READ request, the following
operations take place:
(a) Set n = 0
(a) A request is issued to fill the hardware silo from the floppy media
with sector a+n
(b) The hardware silo is transferred via DMA to the bounce buffer
(c) Set n = n+1
(d) The next request is made to fill the hardware silo again with
sector a+n
(e) The bounce buffer is copied to the user's buffer one word at a time
Repeat (b), (c), (d) and (e) until finished
Normally, during the interleave time, the device driver only needs to
transfer
the silo to the user's buffer. When a bounce buffer is required, the device
driver has the time while the hardware silo is being filled to perform the
copy from the bounce buffer to the user's buffer. So the transfer from the
floppy media is actually bounced off the first data bounce buffer (in a
location
in physical memory which is supported by the hardware) to the final location
in physical memory (where the user's buffer is located). COOOOOOL!!
Jerome Fine
