From: jlowrey@skat.usc.edu (John 'Fritz' Lowrey)
Newsgroups: comp.sys.3b1
Subject: 3b1 Magic POKE?
Date: 15 Oct 1992 11:14:22 -0700
Organization: University of Southern California, Los Angeles, CA
Distribution: usa
NNTP-Posting-Host: skat.usc.edu

        3b1 folk:
        I would like a status check on the DOS-73 to Super-RS232 
conversion.  How are things going, and what can we look forward to?
        My motivation for asking this is to inquire whether you 
have found any "magic pokes" that can enhance the present system in 
the tradition of the "serial.pat" adb script.  As I recall you 
folks mentioned that the 3b1 polled the status of the /dev/ph 
devices every clock tick (60Hz on the 3b1), and you theorized that 
a gain could be gotten by disabling this polling.  This seemed
rational to me, so I decided to look about a bit myself.
	Many of the kernel symbols are noted in /etc/lddrv/unix.sym,
some of these look suspiciouly like routines to handle the OBM and
other /dev/ph things.  Since I have far too much time on my hands,
I went through the list and culled out what looked to me like 
contenders:

/etc/lddrv/unix.sym (3.51m)

connectmodem = 0x1d68a;		<=== OBM
discmodem = 0x1dce6;		<=== OBM
fmodem = 0x1f638;		<=== OBM
foffhookscan = 0x20d82;		<=== OBM **
fonhookscan = 0x20d84;		<=== OBM **
freedialer = 0x1db82;		<=== OBM
freemodem = 0x1db54;		<=== OBM
getmodem = 0x1cffc;		<=== OBM
hangup = 0x1d238;		<=== OBM
hookflash = 0x1d5a8;		<=== OBM
initphscan = 0x1e2d6;		<=== OBM **
modemscan = 0x1dd36;		<=== OBM **
offhookscan = 0x1ccf0;		<=== OBM **
onhookscan = 0x1cd8c;		<=== OBM **
phclose = 0x1c51c;		<=== OBM
phinit = 0x1cfca;		<=== OBM
phioctl = 0x1c5a2;		<=== OBM
phndef = 0x1e922;		<=== OBM
phopen = 0x1c274;		<=== OBM
phread = 0x1c464;		<=== OBM
phwrite = 0x1c4c0;		<=== OBM
pulsedigit = 0x1d40e;		<=== OBM
pulseph = 0x26868;		<=== OBM
ring = 0x1d9d2;			<=== OBM
sermodem = 0x15fdc;		<=== OBM
startcall = 0x1d186;		<=== OBM
switchcond = 0x20d70;		<=== OBM **
teleline = 0x1e9a0;		<=== OBM
telestat = 0x1e9a4;		<=== OBM **
unholdline = 0x1d088;		<=== OBM
waitdialtone = 0x1d832;		<=== OBM
waitringback = 0x1d7b4;		<=== OBM
writedialer = 0x1d504;		<=== OBM

Entries marked with '**' look like the most likely entry point to
a timed status check.
	What seems to me to be the best way of tweaking the current
kernel (at least on my system) would be to disable incoming call
checking.  I have a 14.4kbps modem on /dev/tty000, no Voice Power
card, and little need for the OBM.  However, I do not wish to 
completely kill it as an option for emergency outgoing calls with
cu (one never knows when the macho modem will choke out).
	So, all of this boils down to: what do others think is the
best place to look for placing an "rts" instruction at the entry
point to one of these routines?  Can an appreciable gain be made by 
just tracking down the polling routine and telling it to do its thing
at greater intervals?  Is there something fundamental that I am missing?
Is this a fools errand?
        
				All helpful hints will be recorded,
				Fritz
-- 
        "...now it is my karmic burden         | J. "Fritz" Lowrey
         to stack cat food..."                 | Internet: jlowrey@usc.edu
Newsgroups: comp.sys.3b1