How to tell...
bqt at Update.UU.SE
Tue Jun 21 16:31:02 CDT 2005
On Tue, 21 Jun 2005 Paul Koning <pkoning at equallogic.com> wrote:
> >>>>> "Johnny" == Johnny Billquist <bqt at Update.UU.SE> writes:
> Johnny> Mentec implemented one additional instruction that really is
> Johnny> useful, and which atleast RSX will use, if it finds it, and
> Johnny> that is a block copy instruction. I don't even know if it has
> Johnny> a mnemonic. Moving large chunks of memory is something the
> Johnny> systems does a lot in I/O, so that really helps if it can be
> Johnny> done faster.
> Is that just the MOVC instruction (part of the CIS optional set) or
> something else? If CIS is present, RSTS will use MOVC for block move
No, it's not the MOVC, but the MOVC would probably also be acceptable.
RSX have a macro to define the instruction, called MOVR$
It takes three arguments, in the form of three registers. The opcode is
a is source
b is destination
c is length
all as registers. It copies the data according to this.
RSX detects wether this instruction exists at boot time, and patches the
system if it does, to take advantage of it.
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at update.uu.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
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