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 Post subject: Para FS (STD)
PostPosted: Tue Jul 05, 2005 8:48 pm 
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Joined: Sun Apr 04, 2004 2:19 pm
Posts: 28
Location: Watford
Does anyone know if virtual acorn is compatible with the STD file transfer programme "Para FS"?
I've just ordered a RComp Ultra with VA and want to connect a non-networked Risc PC to it in order to transfer all my files. I've found an old version Para FS with appropriate parellel port lead (the Ultra also has a parellel port) and hope to do it through this.
Any ideas?

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Richard


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 Post subject:
PostPosted: Wed Jul 13, 2005 9:49 am 
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Joined: Wed Oct 23, 2002 10:37 pm
Posts: 64
VA does not yet support use of the parallel port so this will not work, sorry. Your best bet is to buy a cheap network card for the RiscPC.
Graeme


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 Post subject: Parallel Port
PostPosted: Wed Jul 13, 2005 10:06 pm 
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Joined: Sun Apr 04, 2004 2:19 pm
Posts: 28
Location: Watford
"VA does not yet support use of the parallel port..."
Does the use of "yet" mean that parallel ports might be supported in the future? If so, any idea when?!!!

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 Post subject:
PostPosted: Thu Jul 14, 2005 9:13 am 
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Joined: Wed Oct 23, 2002 10:37 pm
Posts: 64
Quote:
Does the use of "yet" mean that parallel ports might be supported in the future? If so, any idea when?!!!

Maybe. No. Even if it does, it will almost certainly not support high speed access as there is so much latency in using byte wise access and parallel port access is notoriously CPU intensive:
RISC OS APP writes a byte
VA 'parallel port' writes to parallel port stream
x86 switches to ring 0
byte propagates down driver stack
windows driver writes byte to port
...
handshake comes back and generates interrupt
...
windows driver receives interrupt
driver signal propagates up stack
event is generated to signal interrupt to VA
...
VA 'parallel port' receives interrupt notification
signals interrupt to virtual arm
...
There are huge latencies per byte. Using a fifo would help and a stream would be even better but RISC OS apps that expect to write a byte and then poll for status are in for a hard time.
Graeme.


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