Table Of ContentehT ROSE 52.X tekcaP hctiwS :.noitacilppA ”DIWC“
samohT .A ,notluoM YV2W
ehT oidaR ruetamA snoitacinummoceleT yteicoS
An application should toh disrupt the
ABSTRACT
normal operation of a ,hctiwiS , nor should it
introduce excessive delays or use large
The purpose of tlhis paper is
stnuoma fo .yromem tI osla y.am be deleted
introducaen dde scribe ehlt DIWC
when no longer need by the network users or
application for the EISOR 52.XtekcaP
,sreganam ybereht gnisaeler yromem rof esu
Switch. In certain countries the need to
sa reffub ro noitacilppa.ecaps
support this function has been raised as a
yrotaluger .eussi ,woN t.a the option of the GNITSIXE DIWC S’LOHTEM
metsyS ,reganaM eht DIWC application
may be loaded and conform to this The existing user TNC code stroippus
requirement. DIWC yb gniyek eht TIP and then toggling
some lines to manually send the CW. This
INTRODUCTION
method could not be usled within the ROSE
52.X tekcaP hlctiwS because many hooks
A general design principle for ROSE
would be needed, and the timers required for
X.25 Packet Switch Applications is to only
the proper keying rate did not .tsix:e This
emusnoc yromem secruoser rof serutaeftaht
approach would clearly consume more code
are needed in a particular Switch or Network
space than could be justified for an optional
of Switches. Any of the optional
application.
applications may be uploaded over the
network on an “as-needed” basis. NEW METHODS
emoS fo snoi.tacilppa that were One method would be olt llif atekcap
developed required installation of special with data that would be sent at 1200 baud in
hooks in the ROSE ;22.X Packet Switch an attempt to sound like CW. There would
EPROM code, but generally these hooks be two data patterns, one for “ON” and one
only use 20-30 bytes of code space. rof ,”FFO“ but the packet required to send
ED“ ”YV2W would be 722 bytes long and
Some of the applications that
more than 1000 bytes for longer callsigns. It
yltnerruc tsixe era ,REDAOL ,GIFNOC
is not clear how well this would sound nor fi
,SRESU ,DRAEH OFNI dna rehtolaiceps
ti_ could be identified as an official CWID.
applications created to debug the system.
The packet size would be quite large and a
egral tnuoma fo UPC em:it would be spent
These applications appear in the
gnitareneg eht
packet.
network as network reachable destination
end points. For example: “C OFNIV
It was tedahehtrtised DTWC sound
102,3-YV2W ,”55S would provide local
much like gnitsixe .smetsys :thT @/l Chip
network information aerA 102 eht rof Code..
used in most sCNT is reh$*e eht 044XZ IKS
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or the 0358Z SCC. These chips have a lot in
common and with some examination of
speeds )MPW( and bit rates elnos interesting
things are possible, CWID should run at
about 20 WPM, which comes to 16 BPS
Due to the nature of the ,JCIS there
MPW( / 1.25 = .)SPB ehT OIS siyllareneg
lliw eb a CLDS galF or two at the trat,s fo
configured for a Xl transmit clock, which
the transmission and a CRC or ABORT at
means that the transmit clock is running
1200 BPS (1500 WPM). With a single O/r eht dne fo eht .emarf o improve ytilibad.aer
the end of the CWID tx:et is’indicated by an
Write the clocking rate (divisor) can be
changed to X16, X32 or X64. The result of AR *
the change is that the clock would be
NEDDIHNOITACILPPA
divided to generate the true bit rate. The rate
of X64 yields 16.75 BPS or 23 WPM. At
The CWID Application is not a
this rate the longest callsign would require
normal application. Since users don’t
31 setyb fo.atad
interact with it over the air, It can be
bundled into another application. The CWID
The hooks required to implement the
has been included in a version of the OFNH
CWID in the ROSE X.25 Packet Switch
application, file name +DOL.DIWCOFNI
EPROM is simply code to set and reset the
baud rate divisor. The ”DIWC“ packet can
ehT OFNI noi.tacilppA contains a
then be included in the normal data stream
couple of features, an OFNI destination that
without major disruption to the port.
will return configurable informational text,
and plain-langua e noitcennocsutats
EDOCNOITCELES
messages to supplement the terse codes
provided in the ROSE X.25 Packet Switch
The next step is to perform tests to
EPROM code, In addition, the text can be in
pick the binary sequences to represent a
either English, Spanish, or German
,TID ,HAD retteL ecapS dna droW.ecapS
The one sequence that must be avoided is 5
NOISULCNOC
l’s in a row, because the HDLC encoding
will insert a 0 bit for its transparency coding.
This exact emrehcs lliw ylno krowrof
1200 baud packet using Bell 202 modems,
The sequence sent for a TID is 01,
but is an example of how other signalling
DAH is 0001, Letter Space is 11 and Word
systems can be built into existing systems.
space is 111. The word space should be
longer, but we would start to get
The ability to remotely load
transparency inserted zero’s, which made
applications into network switches is the
ytilibadaer.tluciffid
single most important platform feature of the
ROSE X.25 Packet Switch and allowed for
IMPLEMENTATION
the rapid implementation and testing of this
elbaulav wen.erutaef
When implementing the ASCII -
Binary CW coder a few interesting items
came up. First, in data communications the
Low Order bit is always sent first. The
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