Path: utzoo!utgpu!water!watmath!clyde!rutgers!husc6!bloom-beacon!gatech!galbp!bing
From: bing@galbp.LBP.HARRIS.COM (Bing Bang)
Newsgroups: comp.os.minix
Subject: tty driver/rs232
Message-ID: <3468@galbp.LBP.HARRIS.COM>
Date: 25 Jan 88 17:58:34 GMT
Reply-To: bing@galbp.UUCP (Bing Bang)
Organization: Harris/Lanier, Atlanta, GA
Lines: 19

well, i finally found that one bug that kept me from posting my tty/rs232
driver. too late though it seems. i'll report the bug anyway.

seems the reason we lose characters from the rs232 ports is that the interrupts
are off in too many places for too long a time. i fixed this by leaving the ints
on and masking off the unwanted ones at the controller. this caused the bug to
show up. in the routine cp_mess, there should be a "cld" right after the "cli"
instruction, in fact, i went through all movs[bw] instructions in the assembler
source files and made sure the direction flag is set correctly. this fix
made my rs232 fast enough for me to use a simple cu to talk to my local bbs's
at 2400 baud without dropping a single character. i have a feeling the same
could be done for jim's driver...

bing

-- 
Bing H. Bang      +--------------------------------------------------------+
Harris/Lanier     |OS/2 on PS/2: Half an operating system on half a machine|
Atlanta GA        +--------------------------------------------------------+