Re: Need help finding a modem for a IIgs

[cdeschu@nyx10.cs.du.edu (Chris Deschu)]

In article <3ap723$hua@carroll1.cc.edu>,
Ron Higgins <rhiggins@carroll1.cc.edu> wrote:
>In article <3aoevg$p49@nyx10.cs.du.edu/ cdeschu@nyx10.cs.du.edu (Chris Deschu) writes:
>/In article <3aksov$d2g@paris.ics.uci.edu>, Orion Pax <jlee@ics.uci.edu> wrote:
>/>Auri Man (aar7334@exodus.valpo.edu) wrote:
>/>: You can use ProTerm and hook up at 57.6, but you won't be able to get the
>/>: full vfast 116.8k (or whatever the super speed is <grin>) until someone
>/>: releases a serial card for the GS that uses the new UART chip that goes 
>/>: to the top speed of a 28.8 modem.  But a 57.6 connection with a 28.8 modem
>/>
>/>It's already been done.  The Turbo ASB serial chip upgrade by Lightning
>/>Systems for the Super Serial Card.
>/
>/Does the turboASB upgrade for the SuperSerialCard alleviate the problem
>/with the one-byte buffer on the original SSC? (Since the buffer is so
>/small, the faster the serial speed, the more often the buffer data must
>/be gathered and cleared, or the data is overwritten by the next byte,
>/and lost.) This means that having interrupt driven code that takes up
>/a lot of time will cause lost data. If this is not corrected in the
>/turboASB, I don't see how the computer could possibly keep up with
>/a 115kpbs connection, let alone 230... Thanks!
>
>No, the Turbo ASB does not solve the one-byte buffer "problem" of the
>original Super Serial Card.  What you say is true, the interrupt routine
>needs to be very efficient or characters will be lost.
>
>I have accomplished data transfers with the DTE rate locked at 115,200
>without the loss of characters on my 8MHz Apple //e.  I have not tried
>transfers at 230,400 yet.

	Interesting. So it appears that it will work great in the
ProDOS 8 environment with proterm (possibly requiring an accellerator),
but probably not under gs/os or gno/me (assuming we get a driver at
some point in the future), because background processes or interrupt
routines will slow the driver down too much. Still, I'd like to see
some tests done sometime as far as the max speed obtainable under
different environments. That speed would be impressive for a null
modem connection (and useful, too!)

-- 
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 |___              Chris Deschu                       cdeschu@nyx.cs.du.edu
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