[Coco] CoCo 2 bitbanger does 57600 bps!
webmaster at coco3.com
Mon Mar 27 20:44:17 EST 2006
At 07:34 PM 3/23/2006, Boisy Pitre wrote:
>Another issue is that protocols like DriveWire are bi-directional;
>the CoCo sends a command, the PC receives it and sends a response.
>Some faster PCs would turn the response around so fast that the start
>bit would be missed by the CoCo. If you're going to build
>reliability into your process you will need some method of passing a
>checksum or other signal back and forth. That turn-around time
>steals cycles from your CoCo that could be used to look for the next
>start bit, so you may have to throttle the PC at those points. Also,
It's true that at 57600 bps over the bitbanger port that a special protocol
has to be used. In my prototype I am using probably the most trickiest
code I've used since some of the self-patching routines in Projector-3, but
no patching is done in my bitbanger code. It's just plain 6809 code that
doesn't change. No PC throttling is needed. It can respond in a nano and
the CoCo won't miss it.
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