[comp.sys.mac] The ROM serial driver

palarson@watdragon.waterloo.edu (Paul Larson) (01/30/88)

Has anyone else had trouble with the ROM serial driver?
Is it unreliable?  I need help.

	Johan Larson

han@apple.UUCP (-- Byron B. Han --) (02/02/88)

In article <4906@watdragon.waterloo.edu> palarson@watdragon.waterloo.edu (Paul Larson) writes:
>
>Has anyone else had trouble with the ROM serial driver?
>Is it unreliable?  I need help.
>
There is nothing inherently wrong with the ROM serial driver (that I am aware
of).  It lacks some of the nicer features that the RAM-based serial drivers 
have, like manipulation of DTR, break stuff, parity error character 
replacement, etc etc etc.

This is NOT an official Apple statement or position.  Just my personal 
experience with the serial drivers on the Macintosh.






-- 
------------------------ Byron Han,  Communications Tool ----------------------
     Apple Computer, Inc.  20525 Mariani Ave, MS 27Y  Cupertino, CA 95014
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rs4u+@andrew.cmu.edu (Richard Siegel) (02/02/88)

I'll second Byron's position on the ROM serial driver. Many moons ago, 
I did extensive work with the serial driver, using it for IEEE-488
data acquisition at speed up to 57.6KBaud, with no problems.

Of course, I did mess up once, closing the drivers at the end of the program. 
:-)

		--Rich

----------------

wwg@brambo.UUCP (Warren W. Gay) (02/03/88)

In article <7305@apple.UUCP> han@apple.UUCP (-- Byron B. Han --) writes:
>In article <4906@watdragon.waterloo.edu> palarson@watdragon.waterloo.edu (Paul Larson) writes:
>>
>>Has anyone else had trouble with the ROM serial driver?
>>Is it unreliable?  I need help.
>>
>There is nothing inherently wrong with the ROM serial driver (that I am aware
>of).  It lacks some of the nicer features that the RAM-based serial drivers 
>have, like manipulation of DTR, break stuff, parity error character 
>replacement, etc etc etc....

I wrote a terminal program as a Desk Accessory once, and I recall that I had to 
resort to RAM drivers.  The ROM drivers (I think) prevent you from specifying
your own buffers, and certainly do not handle the full buffer case correctly.
The default serial buffer is very, very TINY!  In the case of a desk accessory
there was always a chance that the program would be inactive while traffic
suddenly rushes in - bursting the TINY buffer, and eventually creating a bomb.
The RAM drivers permitted me to specify my own LARGE buffer, and enable automatic
flow control, so that if the buffer should get full, an XOFF was immediately
sent even if the desk accessory was put to sleep.

But check this information out first - its been over a year since I hassled 
with this.
-- 
Warren W. Gay - Bramalea Software Systems Inc...!utgpu!telly \ !brambo!wwg
                ...!{uunet!mnetor, watmath!utai}!lsuc!ncrcan /
                "Life is a compromise.  So lets be #pragma-tic."