Columbia Kermit/kermit.zip/archives/msr313src.zip/msvrmx.doc

Text File | 1988-08-16 | 24KB | 461 lines

                     MS-Kermit for the iRMX Operating Systems


INTRODUCTION

Version 2.30  of MS-Kermit, the richest and  most widely used implementation of
Kermit  for the small computer, has been ported to iRMX 86 and iRMX 286.  A DOS
emulator provides enough of  the  DOS  environment  to  allow  the  essentially
unchanged MS-Kermit code to run under both of the iRMX Operating Systems.

This  document discusses differences between Kermit and MS-Kermit, where Kermit
refers to the iRMX  version and  MS-Kermit refers  to the  DOS program.   Users
unfamiliar  with  MS-Kermit  may  prefer  to  read  this  in  conjunction  with
MSKERM.DOC.  Wherever MSKERM.DOC refers to the BACKSPACE key, the RUBOUT or DEL
key is used in iRMX.  Kermit's initialization command file, called MSKERMIT.INI
in MSKERM.DOC, is called KERMIT.INI for iRMX.  (Actually, it's ".INI." suffixed
to whatever Kermit is named.)

Directions for  installation and configuration are included  at the end of this
document.


SYSTEM REQUIREMENTS

An  iRMX system with the usual logical devices :TERM:, :WORK:, and at least one
of :LP:  or :BB: is required.   If :LP: doesn't  exist, Kermit's printer output
will be  discarded.  File transfers  with a local PC  can be accomplished using
the serial  port for the iRMX system's terminal.   An additional serial port is
necessary for file transfers with a remote computer.


FEATURES NOT IMPLEMENTED

PUSH has not been implemented.    Unlike  the  DOS  implementations,  there  is
nothing  that could  be done  with PUSH  that can't  be done  with RUN.   Users
wanting  the convenience of PUSH may RUN the variously named cli CUSP available
in iRMX 286 starting with Release 2, or iRMX 86 starting with Release 8.

SHOW MODEM has not  been implemented.   DSR,  CTS, and  CD information  are not
available from the Terminal Support Code.

VT102, Heath/Zenith-19, and Tektronix terminal emulation, as well as all of the
SET TERMINAL  commands have not been implemented.   You can use the terminal of
your choice and configure Kermit to work with it.

You  cannot transmit  a break  to the  remote computer.   Although  some serial
communication board's firmware  supports  sending  breaks,  the  iRMX  Terminal
Support Code does not.


PATH AND FILE NAMES

Kermit will accept any iRMX  path or  file name  with one  exception.   In file
sending, if the right-most path separator is  ^,  it  must  be  followed  by  a
redundant  /.  For example: ^/UNCLE.FILE and  ^UNCLE.FILE are the same in iRMX,
but only the  first will work  in Kermit.   MS-Kermit doesn't recognize  ^ as a
path separator, so we have to fool it.

Wherever  Kermit accepts a wild  card file specification, a  list of file names
may be used, as long as they are all in the current $ directory.
For example:

        SEND READ.ME.FIRST,*X*.A*,*.OBJ,ETC.ETC

works.  Try to say that in DOS.

When Kermit is in SERVER mode,  operating  as  the  "remote"  Kermit,  it  will
respond to a GET file-name-list from the "local" Kermit.

Kermit will rename incoming files to  match  DOS  naming  rules.    It's  still
basically a DOS program.

The command:

        SEND ,

is  an extension to MS-Kermit that tells Kermit to send those files unsent from
the  previous wild card batch.  If you are  well into a "SEND *", when you lose
your connection to the remote computer, you can "SEND ,", after you reestablish
your  connection, and the SEND will be resumed with the next file from the wild
card batch.  The interrupted file will have to be sent individually.


USAGE NOTES

The Kermit TYPE  command is the iRMX  COPY command.  The  Kermit DEL command is
the iRMX DELETE command.  Kermit will  accept  any  iRMX  DIR  command.    This
applies  to SERVER mode response to REMOTE DEL, REMOTE DIR, and REMOTE TYPE, as
well.  Examples:

        TYPE SAMPLE.FILE TO :LP:
        DEL * Q
        DIR $ FOR *.P86 L

Continuation can be used with the RUN command.  For example:

        RUN ATTACHDEVICE T4 AS COM2 &
        RUN PHYSICAL

is equivalent to:

        RUN ATTACHDEVICE T4 AS COM2 PHYSICAL

Type-ahead from the  entry of a  DIR, DEL, RUN,  SPACE, or TYPE  command to the
next Kermit command input prompt is discarded.

SET DEFAULT-DISK will accomplish nothing.  Use the Kermit CWD command to change
disk drives and/or  directories.  The CWD  command is not the  same as the iRMX
ATTACHFILE command.   Use  CWD :HOME:  where you  would simply  say ATTACHFILE.
Upon exit, Kermit returns you  to the  same $  directory you  were in  when you
called Kermit.

DISABLE SEND  completely disables  sending a  file to  the server,  rather than
restricting its destination to the server's current directory.

When  operating as the remote system, the server returns messages prefixed with
"Kermit-MS".

The  kermit action verbs available for SET  KEY are \Kexit (exit Connect mode),
\Khelp (Connect  mode  help),  \Kstatus  (STATUS  command),  \Klogoff  (suspend
logging), \Klogon (resume logging), \Khangup (HANGUP command), and \Knull (send
the null  character out the serial  port).  These kermit  action verbs are best
bound  to keys that send characters in  the 80-0ffh range or control characters
unused in your dialog with the remote computer.  If ^E, for example, need never
be typed to  the remote  computer, SET  KEY \5  \KEXIT would  make it  a single
keystroke  exit from Connect mode.  The scan codes for keys whose codes are 80h
through 0ffh are \X180 through \X1ff.

iRMX to  iRMX file  transfers are  more efficient  when the  receiving Kermit's
display mode is quiet.  The Terminal Support Code is much slower receiving than
sending.

Faster  machines may need to  use SET SEND PAUSE  for successful file transfer.
This  is especially true when communicating with  IBM mainframes.  The value to
try  is the number of milliseconds  for 2 or 3 characters  at the baud rate you
are using.

On fast machines, the  output  from  Kermit  informational  commands,  such  as
STATUS, may be  quick enough to cause  slow terminals to send  an XOFF.  Kermit
disables  recognition  of  output  control  characters  in  the  input  stream.
Consequently, the ^S is ineffective and becomes the first character of the next
Kermit  command.  Output control character disabling can be overridden with OSC
configuration.

While  SET DESTINATION PRINTER works, it is very slow.  The line printer driver
hogs the processor.   As  a  result,  simultaneous  read/write/compute  is  not
possible.  It's probably quicker to receive  to  disk  and  then  copy  to  the
printer.

If ^W  is used for a paging  display while in the command  being RUN or in DEL,
DIR, SPACE, or TYPE, the Terminal Support Code will deadlock the system.  Users
with iRMX 286 Release 2, Update 2 can obtain the Class B Zaps 110, 112, and 113
from Intel Software Support to  fix this  problem.   iRMX 86  will be  fixed in
Release 8.  A brute force workaround is described under OSC configuration.

Kermit  is a Human  Interface command.   When invoked from  another program, it
should be by sendcommand rather  than  loadiojob.    Kermit's  exit  status  is
returned as  the user fault code  of exitiojob and is  available as the command
exception when Kermit is invoked by sendcommand.  If non-zero, the high byte is
40h; the low  byte  contains  the  values  mentioned  in  MSKERM.DOC,  with  an
additional value of 0ffh meaning that Kermit bombed gracefully.

Kermit  has the appearance of being a CPU hog; the green light burns bright and
steady.  Actually, in the default, Kermit has simply substituted itself for the
idle task.

Kermit  uses a scratch file to implement  wild cards and REMOTE server commands
that return  information.  Failure  to exit Kermit,  such as hanging  up in the
Terminal  Support Code or re-booting  while in Kermit, will  result in an fnode
and possibly some  blocks becoming allocated  but unreferenced.   The fnode and
blocks can be freed using DISKVERIFY.


SERIAL PORTS

There are  ten serial ports, 0 through 9.   Port 0 corresponds to :TERM:.  Port
n, for  n > 0, corresponds to logical name  :COMn: or :Tn:.  At startup, Kermit
looks for the first of ports 1 through 9.  If none are found, a warning message
is issued and port 0 is used, which is only useful when the other computer is a
PC being used as the iRMX terminal.

It  is recommended that logical names for Kermit ports be established either in
R?LOGON or KERMIT.INI.  Either  attachdevice  or  attachfile  may  be  used  in
R?LOGON.  (If  physical device t4 is  hard wired to a  VAX and R?LOGON includes
ATTACHDEVICE T4 AS VAX P  then  ATTACHFILE  :VAX:  AS  T4  may  be  added.)  In
KERMIT.INI, use RUN ATTACHDEVICE or RUN ATTACHFILE.

If  you forget to establish  any Kermit ports, call  up Kermit without noticing
the no port  warning, set the baud  rate and connect, you  will change the baud
rate of your terminal  port.   Although Kermit  refuses to  connect to  port 0,
MS-Kermit  will have already initialized the port, thus changing its baud rate.
The only  recovery is to change  your terminal's baud rate  to match or re-boot
the system.

When a  port whose physical  device name is  the same as  :TERM:'s is selected,
intentional single  port operation is  presumed and Kermit  changes the display
mode  to QUIET to prevent screen displays from conflicting with file transfers.
When a port is  selected that changes  from a one  port to two  port state, the
display mode is restored to its previous value.

The iRMX  Terminal Support Code hangs  up when a DTE  configured port is active
and you either plug or unplug the RS-232 cable.

The iRMX 86 Terminal Support Code, when operating with unbuffered serial boards
such  as the 8251, can accept only a  few characters at 9600 baud before losing
some.   Kermit can  send at  9600 baud  through such  boards, but  receiving is
limited  to 4800 baud.  It  can connect to a remote  computer at 9600 baud, but
will drop some characters if they are sent faster than fast typing speed.

iRMX 286  users can use 9600 Baud with the  8274 device driver, but may need to
restrict receive packet size to about 200 on 286/10's.  There should be no baud
rate problems  on either OS up  to 19200 baud with  buffered serial I/O boards,
such as  the 544 or 188/48.  When  the improved serial device drivers scheduled
for release in forthcoming OS updates  (starting  with  iRMX  286,  Release  3,
Update 1, and iRMX 86, Release 8) are installed, baud rate restrictions will be
reduced, if not eliminated.    The  new  device  drivers  will  improve  Kermit
performance significantly on  both OS's,  especially on  faster systems.   '386
based systems should achieve 56.8 KB with ease.

iRMX 86 R6 and iRMX 286 R1 Terminal Support Code Problems

For middle and  higher baud rates, 1200  and up for the  86/30, the TSC doesn't
overlap read  and compute.   The  consequences are  most noticeable  in Connect
mode, when  nothing will appear on the screen  until the either the remote host
stops sending or is XOF'd.

Serial I/O  results in system clock  slow down.  No,  it's not relativity, it's
probably great yawning chasms of code enclosed in CLI/STI brackets in the TSC.

To solve these problems, use a later release of iRMX.


SINGLE PORT OPERATION

You  can use Kermit on a single port  system, if you have another computer that
you can connect  directly to it.   For example,  connect your iRMX  system to a
PC's  COM port in place  of your terminal.   Call up Kermit on  the PC, set the
baud rate to match your iRMX system, and connect to it.  Use the PC as the iRMX
terminal.   If there are  no logical names :COMn:  and :Tn:, where 0  < n < 10,
Kermit  will automatically select port 0 and change its default display mode to
"quiet", which is necessary for one port operation.

If  you want to change the baud rate  (see above, under serial ports), SET BAUD
before issuing the  SERVER command.   The  baud rate  change won't  take effect
until  the SERVER command.  After issuing the SERVER command escape back to the
PC's Kermit,  resetting its baud  rate, if necessary,  and use SEND  or GET for
file transfer and the REMOTE command for any information you want from the iRMX
system.   When done, issue the  LOGOUT command, which causes  Kermit on iRMX to
exit to the system.   The  terminal's baud  rate and  other attributes  will be
restored  to their initial values.   If you want to continue  using the PC as a
terminal, you may have to change its baud rate back before reconnecting.

In one  port operation, Kermit  refuses to CONNECT.   You may  alternate use of
port 0  with  other  ports  and  Kermit  will  change  display  modes  for  you
automatically.


INSTALLATION

Kermit  and, if you want to do wild card sends, the auxiliary WC command should
be copied to one  of the  default search  directories.   The logical  choice is
:UTILS:, though they both needn't be in the same directory.  If all you have is
the  source for WC, WC.P86, its comment header contains SUBMIT file contents to
make the command for both  OS's.    The  WC  command  isn't  otherwise  totally
useless.  Try entering "WC ?able,movie*"  as  an  alternative  to  "DIR  $  FOR
?able,movie*".


CONFIGURATION

Configuration is  optional.    While  the  primary  configuration  commands  to
consider for initial  installation are  BUFILL and  OSC, this  section contains
enough information on Kermit operation to warrant an initial reading.

The configuration  file, KERMIT.CFG (actually it's  ".CFG" suffixed to whatever
you  call   Kermit),  follows  the  rules  for   Kermit  TAKE  files  with  one
configuration command  per line.   Kermit  looks for  KERMIT.CFG first  in your
default directory,  $.   If not  found, it  looks in  the directory  from which
Kermit  was loaded.  Suppose  you install Kermit by  copying it to :UTILS:TOAD.
The search would be,  first  :$:TOAD.CFG,  then,  :UTILS:TOAD.CFG.    A  system
requiring configuration  for different brand terminals  or for different remote
hosts can configure them all by using a different default directory for each.

In the following  configuration command  descriptions, upper  case is  used for
literal keywords, n  refers to a decimal  number, and \n refers  to a number in
Kermit backslash  notation, i.e.  "\" followed  by an optional case insensitive
radix letter followed  by the number.   Radix letters are D  for decimal, X for
hexadecimal, and O for octal.  If omitted, the radix defaults to decimal.

OSC string

OSC  can be used to configure Kermit's  screen displays to your terminal, solve
the  fast system/slow terminal problem, prevent the ^W deadlock by brute force,
or change  Kermit's default  terminal attributes.   If  your terminal  is VT100
compatible  and is set to send space or no parity or you use SET DISPLAY SERIAL
or QUIET and  you can live  with the "2J01;01H" at the beginning  of the STATUS
command's display, it is unnecessary.

First you must decide if the  regular  screen  formatted  display  during  file
transfers is  what you want.   The iRMX  Terminal Support Code  is reluctant to
permit transparent input  when translation is  enabled.  As  a consequence, you
have the choice between a decent screen format during file transfer, or a fully
functional  keyboard.  When you choose the acceptable screen format, iRMX holds
up  the escape key for one extra keystroke, and if ^E, ^X, or ^Z are needed for
terminal  configuration (several terminals use ^Z for clear screen), they won't
work as  escapes during file transfer.   Also, file transfer  is quicker with a
SERIAL or QUIET display.  On the other hand, opting for the keyboard results in
a hideous screen during file transfer, unless you SET DISPLAY SERIAL or QUIET.

The string is  a valid and complete  OSC sequence WITHOUT the  ESC [ lead-in or
ESC \ terminator (see iRMX 86 Release 6 or iRMX 286 Release 1, BIOS Appendix F;
or iRMX 86 Release 7 or iRMX  286  Release  2,  Device  Drivers  User's  Guide,
Section 2.3).   Any  number of  OSC commands  may be  used as  long as  each is
complete and independent.

The  following example illustrates an OSC  command sufficient for Kermit screen
displays.   It configures Kermit for the  Qume QVT102, Televideo 910 Plus, 912,
920,  925, & 950, and Zentec Zephyr & Cobra terminals.  Let's look at it to see
how OSC configuration works.

        OSC T:T=1,F=1,U=32,E6=93,E30=75,E31=116

        T=1     enables translation
        F=1     vertical cursor coordinate precedes horizontal
        U=32    value for cursor row or column 1.  32 is the code for space
        E6=93   translate cursor positioning to ESC =
        E30=75  translate clear screen to ESC +
        E31=116 translate clear to end of line to ESC T

Referring to the  manual for your  terminal and BIOS  Tables F-4 and  F-5 or DD
Tables 2-3 and 2-4, edit the above to match your terminal.

If your  terminal sends even, odd, or mark  parity, include "T:R=0" in your OSC
to  strip parity from terminal input.  In this case you will not be able to use
SET KEY for characters greater than 7fh, but then, you couldn't anyway.

You can enable  XON/XOF at Kermit command  level with the OSC  "C:O=0".  If you
do, you will  lose ^W (erase word)  at Kermit command level.   It also prevents
the ^W deadlock.  You can retain Kermit's ^W by moving iRMX's ^W to another key
with a control character redefinition OSC.  Since control character definitions
can  not be determined, Kermit can not restore them.  If you want them restored
after  exiting Kermit,  you must  type the  control character  redefinition OSC
manually, or copy a file containing the OSC.

The OSC "T:C23=0" provides  brute  force  prevention  of  the  ^W  deadlock  by
disabling its function altogether.  If  you  want  it  restored  after  exiting
Kermit, you must type the  OSC  "ESC]T:C23=4ESC\"  manually,  or  copy  a  file
containing it.

TRANSLATE

By default,  Kermit disables  TSC translation  when you  connect to  the remote
computer.  The TRANSLATE command enables TSC translation in Connect mode.  It's
possible  to  make  your  non-VT100  terminal  behave  like  a  VT100  if  your
mainframe's  screen editor uses a subset of VT100 escape sequences that the TSC
can translate or simulate.

ESCC

The ESCC command  causes Kermit  to send  an ESC  c, the  VT100 reset,  to your
terminal  on exit.   You may want  to use this  if you have  a VT100 compatible
terminal  or if  you are  unjustifiably optimistic  about the  Terminal Support
Code.  It's  use has been known  to deadlock Release 6  when TSC translation is
enabled.

BUFILL \n

Kermit's  serial input is content paced against a background fill whose default
value is 0ffh.  Some computers and intervening communication equipment (modems,
switches, port selectors, etc.)  send even  or odd  parity NUL  or DEL  as idle
characters.  After baud rate and parity settings, this is the most common cause
of  communication failure  in Kermit.   The  telling symptom  of a  buffer fill
problem  is the appearance of  hanging up some time  after connect, after which
local  escape followed by reconnect clears the hang  up -- even if for only one
character.

If  0ffh (even parity DEL or rubout) is sent by any equipment, you will have to
change the serial buffer fill character.  Values to try include \X7f, \X80, and
\0.  If  there are several black  boxes between the iRMX  system and the remote
computer,  each may  use a  different idle  character.   Multiple tries  may be
necessary to  find a workable  buffer fill character.   If none  of these work,
you'll have to find a character never sent.  The maximum value is 255.

If Kermit suddenly stops  working after  some time  of successful  operation, a
little  research will probably show that the  powers that be did something like
change a data switch from brand X to brand Y.

CIFILL \n

Terminal  input is content paced  against an 80h background.   If your terminal
sends 80h, use CIFILL to change  the  default.    See  the  section  above  for
suggested values.

PRIORITY \n

By default,  Kermit sets  its priority  to 254  to guarantee  more (numerically
lower)  priority for its I/O tasks regardless of how the system it's running on
has been  ICU'd.  This permits it to stay  out of the way in multi-user systems
and  in background operation.  The maximum value is 254.  If Kermit is included
in round-robin scheduling, it will use its full time slice.

SUB-PACK n

This  parameter tunes performance for  file sending.  Send  packets are sent in
bursts of  default size 60.   This optimizes  send performance for  an 86/30 at
19.2  KB with 1000 byte packets.  Decreasing its value increases iRMX overhead,
while increasing it reduces  write/compute  overlap.    Factors  effecting  the
optimal  value include the CPU board, clock rate, baud rate, and packet size as
well as  the performance of the remote  host.  The transmission time/sub-packet
size function has a broad minimum.

CO-DELAY n

This  parameter tunes Connect mode performance.  In Connect mode, output to the
terminal  is allowed to accumulate  and is written every  n system clock ticks.
The default value is 6, nominally 60 ms.  Increasing the value improves Connect
mode performance at the expense of herky-jerk terminal output.

MAX-BAUD n

Users  providing Kermit for clients may wish  to limit the acceptable baud rate
choices  to the most restrictive of their iRMX system, the computer it connects
with,  or intervening communication equipment.   Select the decimal number from
one of Kermit's baud rates.  The Kermit user cannot change the baud rate higher
than  the one specified.  Note that baud  rates 45.5, 134.5, and 113.6K are not
available, because they cannot be expressed in one word.

NO-MODEM

Disables  modem control.  It's been reported that enabling modem control causes
system problems with early, beta test 546, 547, and 548 board firmware.  If you
use  such boards for serial communication,  use this configuration option until
your firmware is updated.  The HANGUP command will not work when this option is
used.

DTR-TIME n

The  duration, in milli-seconds, that  DTR is held down  by the HANGUP command.
The default is 500.

For  the HANGUP command to work,  all of the following must  be true.  The port
must  be configured DTE, the  serial board must support  modem control, and the
system  must have been ICU'd with modem control enabled for the DTE port(s).  A
null-modem cable with a DCE port will not permit DTR control.

ECHO ON or OFF

ECHO  ON causes subsequent CFG commands and TAKE file commands, including those
from  KERMIT.INI, to be displayed.  This  is useful for associating cryptic CFG
error messages  with the  offending line.   ECHO  OFF stops  CFG and  TAKE file
echoing.

KILL \n

Creates a "kill Kermit" task  associated  with  the  terminal  input  character
specified by the  parameter, usually an  unused control character.   Useful for
developers, incorporators, and anyone trying to figure out how to connect a DTE
port to  their remote computer for the first time.   This will not solve the ^W
inspired TSC deadlock.  Only killing the job from another terminal or warm boot
will do.