[Coco] [Color Computer] X10 driver

[Gene Heskett]

On Tuesday 26 June 2007, Ries, Rich (S&FS) wrote:
> Check out ftp://ftp.x10.com/pub/manuals/technicalnote.pdf -- the Tech
>notes for the PL-513 (one-way) and TW-523 (two-way) X-10 interface
>modules. Using these /may/ be better than trying to dig up an old RS
>CoCo interface.

Not always the case when using that data, see below.

> Note that X-10 comms is based on the AC zero-crossing, and is set up to
>work with three-phase power mains. To me this means the firmware must be
>interrupt-driven. I am not too sure that OS-9 works too well with
>interrupts other than its own. Perhaps a micro-controller interface
>board could be designed to accept X-10 commands from the CoCo, and send
>them out to the X-10 interface module.

That timing concern is pretty much a non-starter Rich.  The timing lags in the 
rs-232 protocol are many times larger than any interrupt latencies.  The 
devices themselves do time the data pulses using 120hz interrupts, but that 
is completely internal and only starts after a command has been received in 
its entirety by the device, or does for the cm11a and cm17's.

And I would again ask that those interested in learning the protocol, should 
NOT rely on the data pdf from x10.com, its incomplete and in some cases 
erronious.  For the latest version, derived from very extensive testing over 
many years, go and get the heyu2-beta.11.2.tgz file from the heyu site:
<http://heyu.org/download> and extract the file 'protocol.txt' from that 
archive.

>HTH,
>--Rich

-- 
Cheers, Gene
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