[Coco] Source code for High Speed Bit-Banger I/O

[Roger Taylor]

At 07:42 PM 4/26/2007, you wrote:
The speed increase, interleaved checksum, framing error detection, 
variable request count and termination due to a pause in the 
transmission were all my own enhancements.

>I tested both the 57600 and the 115.2K operation on a CoCo 3 
>connected to my PowerMac G4 through a KeySpan High-Speed Serial 
>adapter and the serial cable I bought from you. All my tests worked 
>flawlessly (I have transferred whole disk images both ways without 
>any data corruption).
>
>Darren


Good job, then.  If it works, then I guess I can't claim to be the 
only one who made it possible.  :)

Now, my own 115.2k model definately uses some strikingly similar 
areas of the code you posted, but then I adapted it from the comm 
source as well.  The 16,15,16,15,16,15,16,15 cycle timing is really 
the only way to do it for syncing the received bits, so that part is 
a given no matter how you code it.  :)

However, my model and protocol was designed to work in a 
background-driven environment.  The CoCo can literally sit there with 
a flashing cursor and talk to a PC at 115200 bps with nothing 
missed!  This is on a CoCo 1, 2, or 3 and no GIME or IRQ/FIRQ 
involved!  What about a PC running at 3ghz and well enough capable of 
transmitting too quick while the CoCo is possibly executing a slow 1 
or 2mhz instruction.  Solved!  :)




-- 
Roger Taylor