Serial comm differences between PC & Mac?

[Dar Scott]

On Dec 3, 2004, at 9:24 AM, runrev at jkvaldez.com wrote:

> Your results are interesting, if not confusing. Do you think this is a 
> bug
> (& therefore should be entered in bugzilla)?

IIRC, it looks like 3 bugs:

Char read commands come up short on XP for reading 256 chars.
Multi-char read commands throw away data after LF on OS X.
Codes 10, 11 and 12 are garbled in reading uint1 on OS X.
Multi-uint1 read commands sometimes come up short on OS X based on 
garbage at end (?).
uint1 read commands input garbage if the data is not there.


> Fortunately, since the phone system only uses a certain set of chars, I
> can filter out all of the junk, & make this work for my needs. BTW, I'm
> using both the keyspan usa-28 & usa-28x on OSX, & com1 on the PC. The
> results are the same with either keyspan adapter.

It looks like you might get garbage if you try to read a uint1 and none 
is there.  The time might come when one of the garbage bytes looks like 
a valid letter.

It might be that my short data for 256 char reads does not apply to 
single char reads.

There are several reported bugs for serial on OS X; you will have to 
work around those.

Windows serial I/O is blocking (up to 2 seconds) and OS X serial I/O is 
not (except for a weird OS X feature in opening the modem where a 3 
second delay is forced).

I think someone (Sarah?) has reported better luck with usa-28 than with 
usa-19.

I suspect that Rev is not setting some terminal parameters on ports, 
leaving them as they are, on OS X.

Dar

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