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Re: cable

In article <xm19RoF.bradbuchner@delphi.com>,
Brad Buchner  <bradbuchner@delphi.com> wrote:
> I am trying to figure the pin points for my USR Sportster 28,8 to my
> Apple IIGS

The standard "high speed" modem cable should work (IIgs flow control
lines connected to RTS/CTS at the modem, DCD signal from modem to IIgs
DCD input, outgoing handshake may optionally be connected to modem DTR
pin as long as you have &D0 in your INIT string).

> I can transfer data at 19.2 just fine but when I go higher than that
> it always gets a quit a few errors.  I use Proterm 3.1 for my
> commuting and it always loses a few blocks from the modem to the
> computer.  Would there be something in my system program that it
> doesn't like to run with.  Here are the slots that I use
> slot1  Appletalk

Bingo.  Any time a packet is sent or received over AppleTalk, there
will be a long delay in processing interrupts from other sources.
This would cause character loss at high speeds (especially higher than
19200).

If the network is sitting idle (e.g. you only have IIgses and printers
connected) then very little data will be sent over it, and modem comms
should go reasonably OK at 19200.  I have a very similar setup to you
(I'm using Spectrum), and I can't get reliable file transfers going
at port speeds faster than 19200 bps.  I have an idle AppleTalk network.

If the network is in use (especially if there are any file servers),
you may find that characters are lost at 19200 - you may be forced to
use 9600.


We need a high-speed serial card with on-board buffering...
-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand