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Re: Recode to Play MP3?



mdj wrote:
On May 20, 5:31 pm, "Michael J. Mahon" <mjma...@aol.com> wrote:

Michael Kent wrote:

Michael J. Mahon <mjma...@aol.com> wrote:

Michael Kent wrote:

schmidtd <schmi...@my-deja.com> wrote:

I wonder if Dave Schmenk's 30% faster CFFA firmware would help?

It doesn't look like it.  His firmware doesn't seem to affect GS/OS
access, and both Oversampler and LongPlay are GS/OS programs.

Have you installed Dave Lyons' GS/OS CFFA driver?

Yes.

I wonder if the read (and/or write) speed of the CFFA is influenced
by the speed of the CF card?

Theoretically, a "1x" card would support 150KB/sec, so unless there
is something peculiar going on, *any* CF card should be about as fast
as an Apple could transfer data--and much faster than the 11kB/sec
that sampled sound would require.


It seems the CF cards have unusually long setup times for data
transfer that considering the typically small IO transactions that
Apple II's do, severely impacts the total I/O throughput you can
achieve - apparently to the degree that even 1980's class hard disk
drives can outperform it.

The hardware design of the CFFA would need to incorporate some sort of
asynchronous buffering that enabled the CF card to be read and filling
a buffer while the card firmware emptied it.

This would be a very different CFFA design, since the CFFA does not
include a microcontroller.

I've not looked at the CFFA's design in detail, but I'm fairly certain
it doesn't utilise a technique like this, and as a result manages only
modest data transfer rates.

All data handling and card control (apart from hardware handshakes)
are done by 6502-based firmware.

-michael

NadaNet file server for Apple II computers!
Home page:  http://members.aol.com/MJMahon/

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