UUCP using V.32 or HST modem connections

[Mark Whetzel]

In article <670532360.4967 at mindcraft.com>, karish at mindcraft.com (Chuck Karish) writes:
> In article <1991Mar30.032817.7885 at hybrid.UUCP> mdapoz at hybrid.UUCP (Mark Dapoz)
> quotes <1991Mar28.110956.10576 at unislc.uucp> sun!jkimble at unislc (Jim Kimble):
  [ discussions of VRM and ect, deleted ]
> 
> This is the first I've heard about a "fix" for this one, and I've been
> bugging the support people about it for two years.  If I have the 6150
> talk to my TrailBlazer at 19200 baud, it loses characters.  The
> machines has a buffered 4-port adapter (16550 UART chips) and it works
> at 9600 Baud max, which gives me 700-800 cps on UUCP transfers.
> 
> The UUCP symptom is that uucico times out and kills itself with an
> assert(), telling me that it's at line 365 in program pk1.c
> 


I currently use a T1500 trailblazer for my uucp connections to uunet all
the time without any loss of characters.  I am not sure of performance, but
I have never measured thruput (or how to find out :-)   I am running
on an IBM RT 135 running AIX 2.2.1 at maint level 2706+1773 using the internal
serial port (S2) for 19200 baud connection just fine.  I have it setup to
use DMA channel zero.  It works like a charm!

Here is excerpt from my devices setup:
                                        Current  Possible
Name      Description                   Choice   Choices

biopa     First I/O Port Address        8001     8001
cn        DMA Channel Number            0        0          <<<NOTE!
ae        Automatic Enable              delay    true,false,share,delay
bpc       Bits Per Character            8        5,6,7,8
pt        Parity Type                   none     even,odd,none
rts       Receive/Transmit Speed        19200
pro       Protocol                      dc       dtr,cdstl,dc
ixp       Include Xon/Xoff Protocol     false    true,false
dvam      Device Attachment Method      1        0 = local, 1 = remote (modem)
noi       Num. of Interupt Levels Used  2        2
pn        Port Number on Adapter        0        0
dmas      DMA Support                   true     true,false <<<NOTE!
sdmac     Shared DMA Channel            false    true,false
ei1       Enable 1st Interrupt Level    true     true,false
si1       Share 1st Interrupt Level     true     true,false
ic1       Service Class of 1st Interpt  0        0,1,2,3
il1       Intrpt Level # of 1st Intrpt  2        2           <<< NOTE!
ei2       Enable 2nd Interrupt Level    true     true,false
si2       Share 2nd Interrupt Level     true     true,false
ic2       Service Class of 2nd Interpt  0        0,1,2,3
il2       Intrpt Level # of 2nd Intrpt  13       13


I have heard of performance problems with both the 4-port and 8-port
adapters from IBM.  If you look in the
"User setup guide and options installation" book, on page 1-21 you
will see that the internal ports use DMA channels AND interrupts for I/O
(it uses IRQ 2 and 13, which is reserved for just this purpose!)
whereas the other ASYNC cards use only interrupts!  No wonder they overflow
especially on a hi-speed link and with any users on to delay service of
the cards!

Later,
markw
-- 
Mark Whetzel     My comments are my own, not my company's.
Western Geophysical - A division of Western Atlas International,
A Litton/Dresser Company           DOMAIN addr: markw at airgun.wg.waii.com
				   UUNET address:  uunet!airgun!markw