Message-ID: <4035@decwrl.UUCP>
Date: Mon, 29-Oct-84 09:16:06 EST
Article-I.D.: decwrl.4035
Posted: Mon Oct 29 09:16:06 1984
Date-Received: Tue, 30-Oct-84 08:16:47 EST
Sender: daemon@decwrl.UUCP
Organization: DEC Engineering Network
Lines: 22



I known nothing about the Microbits modem, but the Atari joystick ports are
parallel output via a standard PIA (peripheral interface adaptor) chip off 
the 6502's internal bus.  Therefore I see no reason why the speed limit
should be any where close to 13 bytes/second (parallel equivalent of 130 baud).
I imagine that the program limits it more than the hardware.

The rumor about 130 baud may have arisen form the fact that the Atari 
internal operating system samples the joystick ports at n times/second (60?)
and copies the data into "shadow registers" in RAM.  Thus, if you check the
input from the PIA by looking at the shadow registers, then there is 
certainly a low speed limit.  I don't think it is very likely that this is
how uBits does it, however.

Burns


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