[Simh] Simh Digest, Vol 90, Issue 16

Timothe Litt litt at ieee.org
Mon May 23 14:05:37 EDT 2011


The /NOTYPEAHEAD will prevent login.  This was probably done because you had
random hardware devices (e.g. the UTC clock mentioned in the comments) on
the lines, and didn't want to start a login if the device talked before your
controlling program got started.  It was also done (see txa 4-7) to prevent
noise on an open line from starting a loginout process - that would time out
- and restart forever.  With errors in the operator log.
 
The /ALTTYPAHEAD on TXA0 is giving you a different (usually larger - it's a
sysgen parameter) type-ahead buffer.  This was useful when you had a device
that didn't respond - or responded slowly - to flow control.
 
/MODEM indicates that the line supports modem control.
 
/HANGUP is what tells loginout to hangup the line on logout - this is what
tells a modem to hang up, and telnet to disconnect in the simh emulator.
 
/DMA says to use DMA for terminal output (to off-load the CPU).  With some
interfaces, this wasn't recomended because it delayed flow control - early
terminals didn't have enough buffering.  DH11 had this problem, but later
interfaces like the DHV could control the DMA based on flow control from the
terminal, and so didn't over-run.
 
The login prompt on a non-autobaud line should be, er, prompt.  Make sure
you don't have external authentication configured - this could cause delays
while it figured out if login was allowed - not 20-30 sec - that sounds like
a timeout trying to reach some process.  What do the operator and error logs
say when this is going on?
 
$ help set terminal should help you to understand what's going on instead of
guessing.  If you have access to the OLD or hardcopy notebooks, the terminal
device driver manual will also help.  I think there's more setup information
in the system mangers' manuals - but I don't recall the exact location.
 
VMS is actually pretty well documented; this stuff isn't as mysterious as
folks seem to think.



---------------------------------------------------------
This communication may not represent my employer's views,
if any, on the matters discussed.
  

 


  _____  

From: simh-bounces at trailing-edge.com [mailto:simh-bounces at trailing-edge.com]
On Behalf Of Larry Baker
Sent: Monday, May 23, 2011 13:38
To: tivo.overo at gmail.com
Cc: simh
Subject: Re: [Simh] Simh Digest, Vol 90, Issue 16


Gary,


Here's most of the SYS$MANAGER:SETUP_TERMINALS.COM we used on a MicroVAX
with a DHQ11.  Port 0 was connected to a real modem, for dial-up terminal
access.  We hardwired the speed; you shouldn't have to with a telnet port.


$!
$! DHQ11 (TXA0:..TXA7:)
$!
$! TXA0:  Telebit Trailblazer dial-up modem
$!
$! Telebit modem parameters for auto-answer:
$!
$!E0 F1 M1 Q1 T V1 X1     Version BA4.00
$!S00=001 S01=000 S02=043 S03=013 S04=010 S05=008 S06=002 S07=040 S08=002
S09=006
$!S10=007 S11=070 S12=050 
$!S45=255 S47=004 S48=000 S49=000
$!S50=000 S51=004 S52=002 S53=002 S54=000 S55=000 S56=017 S57=019 S58=003
S59=000
$!S60=000 S61=045 S62=003 S63=001 S64=000 S65=000 S66=001 S67=001 S68=255 
$!S90=000 S91=000 S92=000 S95=000 
$!S100=000 S101=000 S102=000 S104=000 
$!S110=001 S111=255 S112=001 
$!S121=000 
$!
$ If ( F$GetDVI ( "_TXA0:", "EXISTS" ) )
$ Then
$    Set Protection=W:RWLP _TXA0: /Device
$    Set Terminal _TXA0: /Eight_bit /Pasthru /Hostsync /Modem /DMA
/Disconnect -
                         /NoAutobaud /Altypeahd /Hangup /Dialup /Speed=9600
-
                         /Permanent
$ EndIf
$!
$! TXA1:  Not connected
$!
$ If ( F$GetDVI ( "_TXA1:", "EXISTS" ) ) Then -
$    Set Terminal _TXA1: /NoType_Ahead /Permanent
$!
$! TXA2:  Kinemetrics/TrueTime GOES Clock
$!
$ If ( F$GetDVI ( "_TXA2:", "EXISTS" ) )
$ Then
$    Set Protection=W:RWLP _TXA2: /Device
$    Set Terminal _TXA2: /NoEcho /NoEight_bit /Pasthru /NoAutobaud -
                         /NoType_Ahead /Altypeahd /Speed=1200 /Permanent
$    Assign/System/Executive_Mode/Translation_Attributes=Concealed -
        _TXA2: UTC_Clock:
$ EndIf
$!
$! TXA3:  VT100
$!
$ If ( F$GetDVI ( "_TXA3:", "EXISTS" ) ) Then -
$    Set Terminal _TXA3: /DMA /Permanent
$!
$! TXA4:..TXA7:  Not connected
$!
$ If ( F$GetDVI ( "_TXA4:", "EXISTS" ) ) Then -
$    Set Terminal _TXA4: /NoType_Ahead /Permanent
$ If ( F$GetDVI ( "_TXA5:", "EXISTS" ) ) Then -
$    Set Terminal _TXA5: /NoType_Ahead /Permanent
$ If ( F$GetDVI ( "_TXA6:", "EXISTS" ) ) Then -
$    Set Terminal _TXA6: /NoType_Ahead /Permanent
$ If ( F$GetDVI ( "_TXA7:", "EXISTS" ) ) Then -
$    Set Terminal _TXA7: /NoType_Ahead /Permanent

Larry Baker
US Geological Survey
650-329-5608
baker at usgs.gov

On 21 May 2011, at 6:52 AM, simh-request at trailing-edge.com wrote:


Date: Sat, 21 May 2011 08:52:09 -0500
From: Gary Lee Phillips <tivo.overo at gmail.com>
To: Mark Pizzolato - Info Comm <Mark at infocomm.com>
Cc: simh at trailing-edge.com
Subject: Re: [Simh] VAX DZ terminal controller unit?
Message-ID: <BANLkTikYFGRY6mRo2aC5BQ3AuxDNbh=rzA at mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

Thanks, Mark. I was planning to try the VH emulation this weekend, in
fact. I'd held off because I wasn't sure I could use a Qbus device
with the Microvax emulator, and thought I might have to build the
11/780 emulation instead.

I have more information on the DZ, too. After much blind and random
experimenting, I found that using this command on the VAX side will
make the TTAx ports behave in a somewhat more predictable manner:

SET TERM TTAx -
 /MODEM -
 /DIALUP -
 /HANGUP -
 /DISCONNECT -
 /NOAUTOBAUD -
 /PERMANENT

Note that these settings go away when the VAX is rebooted, so they
probably should be added to SYSTARTUP_VMS.COM or some other script
that will reset them after a boot.

By setting those flags for each of the ports on the DZ, I get a
consistent result. The telnet session is completely disconnected on
logout, closing the telnet window, and no _TTAx process is left
hanging around on the VAX side. The remaining issue is some slowness
in getting up a prompt when first connecting, and that may be related
to what you've described here. I find that it takes 20 to 30 seconds
for the login prompt to appear after pressing the ENTER key, but after
that everything works well.

I'll give the VH a try, possibly today.

--Gary




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