The Quick and Dirty Unofficial Help File for Nino IZ8BLY's Chip 64 Software

By Andy K3UK

Revised 24/9/05

This is a  temporary English language help file for this new amateur radio mode, intended to serve until an official version is released.  For more information on the mode, please consider joining the Yahoo Group dedicated to this mode at http://groups.yahoo.com/group/chip64  or the Digital Radio reflector at http://groups.yahoo.com/group/digitalradio/  

If you are a member of the  Chip 64 Yahoo Group, a detailed description of this mode is available in the FILES section  http://groups.yahoo.com/group/chip64/files
 

What is it ?  A digital mode for amateur radio communication.  It is a phase shift keying application that utilizes some spread spectrum methods.


How do I get the software ?     Go here and download the file.  Install on to your computer.

How do I make it work?      We will assume that you already have a  amateur radio licence and  suitable transceiver that is connected to your computer via a suitable interface.  If you do not, please go to http://www.qsl.net/wm2u/interface.html  for basic instructions on how to connect the output of your computer soundcard to the input of your transceiver, and the output of your transceiver to the line-in of you soundcard.  

Assuming you have your radio and PC interfaced, getting started with Chip 64 is easy.  Boot up the software  and you will see a screen ...illustrated below (I will make a better screen capture at a later date).



Chip 64 Screen Shot
I may add some graphic illustrations of certain task, later when I get more time.

Set the software to control your transceiver:  Your radio will need to "talk" to the Chip 64 software and cause it to key/un-key your radio as you alternate between transmitting and receiving.  To do this,  you need to click on the WRENCH (Spanner) ICON in the upper left top of the screen.  When you do this, a dialogue box will open and you will see several options.  Click on  PTT PORT.  Choose a Comm Port that you wish to use.  Chip 64 works well  via regular comm ports and virtual USB comm ports such as those used by Microkeyer.


Programming in your callsign and other personal information:   Next, click the Wrench Icon again, this time choose General.  Enter your call sign and personal information in the spaces provided.

Setting up a few Macros (or "buffers") :  While Chip 64 is a slow-typist friendly keyboard board mode , you can save yourself some time and effort by pre-programming some macros with personal information.  Chip 64 already comes with a  some general content for you to use.  I would suggest you check the macros at the  bottom of the screen by RIGHT CLICKing on each one and adding your personal touch.  The average user will want macros them to  at least include CQ,  QRZ, Station Information,  Name/QTH,  and one I call a "RETURN"  macro (simply mycall de their call , or in Chip 64 syntax  :   $OTHER de $QRZ   )
If you make a macro that you wish to also handle the automatic switching from transmit to receive, your macro should end in       $off   .

Nino IZ8BLY is the author of other amateur radio software including a MT63 application called Stream.  In Stream,  he appears to use the same syntax for macros that he uses in Chip.  Therfore, it appears logical Stream macros will work in Chip .  They are;


Metacommand

Text sent / action taken

$QRZ

The station callsign (as typed in the Preferences window)

$OTHER

The other party's callsign (defined with F11 key)

$CQ

Sends standard CQ call

$UTC

Time stamp (UTC time)

$TIME

Time stamp (local time)

$DATE

Date stamp (referred to local time)

$DATEUTC

Date stamp (referred to UTC time)

$$

The dollar sign (otherwise not printable)

$Cnn

Sends ASCII character number nn, e.g. $c65 sends "A"

$BUTTONn

Sends text assigned to the user definable button n (ranges is from 1 to 12)

$NOQSO

Clears other party callsign ($OTHER).

$Pn

Sets the output power level (soundcard volume) to n.
The value ranges from 0 (silence) to 255 (full volume)
.
This metacommand influences the mixer setting.

$OFF

Closes the transmission and goes in RX mode

$LASTSNR

The signal report of other party measured on last transmission. The values is in S scale as for transceivers (0...9, 9+5...9+60)

$LASTCONFIDENCE

The best measured confidence percentage of the last transmission (0-100%).

Thanks to Ron W4LDE for this information.

OK, I've set up my rig, computer, and programmed in my call sign, now what ?     Well, there is not much more but perhaps you should double check which MODE you are in.  Chip 64 usually defaults to Chip 64 but you can also transmit/receive Chip 128.  Most people use Chip 64, so I suggest you start with this.  Go to  MODE in the upper left of your screen and make sure Chip 64 is checked (ticked).  While there, check to make sure UNCLOCKED  DECODER is checked.  Most people seem to use the UNCLOCKED DECODER although some users start QSO in difficult conditions with a CLOCKED DECODER.


RECEIVING CHIP 64/128 . :

 While there is A LOT to this new mode, there is not much more you need to do other than get to experience the mode in action.    Turn your radio on, if you have it interfaced correctly you will see graphic evidence of received radio signals,  or atmospheric conditions,  via the WATERFALL that is  towards the bottom of your screen..  The default Chip 64 setting appears to be such that received signals appear as white vertical lines on the waterfall.  I suggest that you tune your radio to a known active PSK31 or CW part of a band just to get used to how received signal appear on the waterfall.  After you have done that,  and know what received signal generally look like, it is time to look for an actual Chip 64 signal.  In the USA,  7090 USB appears to be the most active frequency,  14110 and 14077 have also been reported.   Check the Chip 64 reflector for more frequency information specific to your region.    On 7090 there is also Olivia activity, Olivia has a chirpy sounding tone, a kind of combination of MFSK16 and SSTV sounding signals.  Chip 64 is nothing like  this , it is more a "whooshing" or "roaring" white noise type of signal, not as low in tone as MT63.  If you REALLY want to hear what it sounds like just  put your Chip 64 software in transmit mode (see below) without the radio on , and you will hear it via your computer speakers or headphones. If you hear a Chip 64 on your radio, the Chip 64 waterfall will graphically display the signal, in a whitish colour , about 300 to 400 Hz wide (on the waterfall scale).  To decode the signal,  simply place your mouse in the middle of the received signal and with a few short seconds the received decoded text should start scrolling on your screen.  What is the SECOND waterfall below the first one?  Don't worry about that, more later.   If you successfully receive text, that's pretty much it.  If  you have strong signal and cannot decode, make sure the AFC box is checked and that you are in Chip 64 not  Chip 128.

My received text is mostly gibberish although I see a few normal words?
   Weak Chip 64 text is similar to many other digital modes,  when they fall below a threshold... errors are produced.  Sometimes random characters are displayed .  You may want to adjust the squelch setting (WRENCH  icon, GENERAL, DECODER OPTIONS)  to a higher CONFIDENCE LEVEL.... 50% seems to work well.  Turn OFF the squelch  via unchecking the SQUELCH box in the CONFIDENCE LEVEL  pane , lower right at the bottom of the Chip 64 screen,  if you want to pull out a very weak signal.

What is this Unclocked/Clocked  Thing? 
According to the author, Nino IZ8BLY, "
with 'clocked decoding' the signal is decoded in the traditional way, that is, without taking advantage of spread spectrum. In this case a clock reference is extracted from the incoming signal and the decoder tries to maintain synchrony with the symbols. Additionally, the shape of the detected symbol (See the "chip shape" pane , lower right of your screen) ) is displayed in a dedicated box. There might be some conditions where clocked decoding performs better than unclocked one, just experiment with the two."

What Is the difference between Chip 64 and  Chip 128?  Nino Iz8BLY states "Chip128, it is the slower but more reliable version of Chip64, obtained by doubling the spreading code length. Nonetheless, the baudrate and bandwidth is the same as in Chip64".  I (K3UK) have had several QSO in Chip 128 and can confirm that it appears to improve decoding under QSB-type conditions.  As yet, I have nottrained  my ear to tell the difference in sound, if there is any, between the two Chip modes.

Hey, There Appears to be TWO Waterfalls.  Just What Does the Lower One Do ?  The lower one is called The Correloscope.  Nini IZ8BLY describes it thus

 " The program features a special display called correloscope. It shows the presence of the code by displaying its time-offset. The correloscope plots in a graphical way the output of the correlator. On the horizontal axis, the time frame of a code- length is represented (1/300 sec). At each sampling step, one dot is drawn: the more the correlation confidence, the whiter the dot plotted. By plotting the correloscope in a waterfall fashion, the user is able to perceive how the offset of the received codes moves over time. A distur bed signal will plot an unsteady vertical trace (where the shape of this trace depends on the propagation conditions ). A weak signal will plot a steady but faint vertical trace. The correloscope can also show possible clock drifts between the transmitter and the receiver, which are seen as slanted traces. The output of the correlator also controls the squelch of the receiver which is turned off when the confidence falls below a certain threshold. The software has also the option to turn off the correlator and demodulate the signal as a traditional BPSK transmission (referred in the program as "clocked decoding"). Its purpose is to show the differences between the two decoding systems under different conditions. By averaging chips phase errors, a very smooth frequency tuning is possible. This is indeed another advantage of Spread Spectrum. The averaged phase errors, constitute a stable frequency error correction signal that can be put in feedback to the main NCO allowing an automatic and precise frequency tuning.  The correlator In the decoding process, each receiving sequence has to be matched with the WHP codes from the alphabet, that is, the despreading process has to be repeated for every WHP code. This is necessary because in this system we haven’t just a single code as in plain DSSS, but multiple codes present serially and randomly at the receiver. Thus, each chip from the arriving sequence is compared with the corresponding chip of the reference WHP code in the table. If the chip sign matches, confidence is augmented; otherwise if the sign doesn’t match, confidence is decreased. At the end of the chips, the resulting confidence for that code is obtained and the matching work is repeated for all the other WHP codes in the table. The time-offset of the arriving code sequence is calculated as the point with best confidence over a code duration, and the corresponding code is used for decoding into text. For better performances, soft chips are processed. A soft chip is a chip that does not represents discrete states (+1 or -1) but represents the likelihood of the chip of being "+1". This likelihood system provides a better accuracy giving a continuous range in the confidence values, rather than discrete steps of 1/64. The soft bit information is derived directly from the phase error output of the BPSK detector. Soft bit values range linearly from 0.0 (0° angle) to 1.0 (180° angle). To avoid in between chip synchronization, the despreading work has to be done in time steps smaller than one chip , thus picking with greater precision the offset point of the code. This is done by working with an oversampled signal respect to the chiprate. Depending on the CPU speed, three oversampling figures are provided: 21x, 7x and 3x; these apparently odd figures, are all divisors of 44100 Hz, the samplerate used by the soundcard. An higher oversample gives to the correlator a better resolution, but has an heavier load on the CPU. The CPU load is an actual limitation, as it can be too high to let the program run on some old PC workstations. The load is proportional to the number of elementary chip matching operations that can be executed in the time unit. Since these elementary operations translate into simple ADD and SUB register machine code instructions, they can be executed in just one CPUclock cycle, therefore the total CPU load (lower bound) can be approximately calculated as:

ncodes chiplength oversample chiprate nop ´ ´ ´ =

For Chip64: nop = 300 × 21× 64 × 128 = 51,609,600 ˜ 50 Mips

For Chip128: nop = 300 × 21 × 128 × 256 = 206,438,400 ˜ 200 Mips

With current CPU clocks in the range of few GHz, it’s necessary that the correlator has the maximum  possible performance. For this reason, integer math was used as it guarantees faster execution speeds
than floating point math. In particular, the correlation
routine was written in pure assembler doing all  operations in CPU registers and interlacing the machine language instructions to take advantage of the
processor’s execution pipeline.


Transmittting Chip 64 /Chip 128

OK. Receive is OK, how do I transmit?  First, like any digital soundcard mode.. you need to make sure your signal is "clean", free from ground loops and other nasty causes of "hum" .  You also need to set your output level to one that will not overdrive the produced signal.  I would suggest starting off with a low power signal , nothing more than 30 watts .  Getting a clean signal is usually not a problem if you have an interface like Microkeyer , Rigblaster, or similar commercially made products.  Home brewed interfaces can be made for less than US$15.00. A good clean signal also requires the right combination of volume output from your computer and gain setting on your rig.  Other digital modes usually advise one to turn up the gain to just about the point that your meter starts to show the slightest ALC , then back off a little more.  Chip 64 has a convenient OUTPUT POWER slide adjuster, just to the right of your macros section.  Sliding the lever will increase your soundcards output to the radio, as you increase or decrease the output you will see the gain on your radio output meters change, assuming your rig is in transmit..

Enough already, I know all that stuff...I just want to get on the air.    To answer a CQ call or respond to a CQ call , you need to get the software to key your rig.  Chip 64 automatically goes in to transmit mode if you place your cursor to the transmit text window, located just above the waterfall.  After you place the cursor there, pressing any key on your keyboard will start the transmit.  You can either manually type your transmitted text or use some of your pre-programmed macros.  Most people use a combination of both.  When you want to end your transmission  you can choose a macro that has an $off command at the end, issue a CONTROL X from your keyboard ,  or go to the top of your screen and select TRANSMIT then end transmission..  It is generally best to  transmit with the waterfall frequency  ( lower right hand corner of your screen) around the 1300 to 1700 range , outside of this range and weird things happen when you transmit.  I'll leave that to someone else to explain.  Chip 64 will conveniently center itself on 1500 Hz if you simply RIGHT CLICK on the waterfall.  IF you want to change the RIGHT CLICK results to a frequency other than 1500 Hz, go to  WRENCH ICON,  WATERFALL,   and then change the frequency in the  WATERFALL DISPLAY RANGE /RICK CLICK FREQUENCY box.  You can also change some of the default  ranges for your waterfall in this area.

Can I TYPE AHEAD?  Yes you can.  To do this you must start your to-be-transmitted text with an asterisk ( * ).  Anything you type after the asterisk will not be transmitted UNTIL you send a CONTROL T from your keyboard. 

My Macros don't seem to send the other person's info !  Macros like  $OTHER  , $OTHERNAME ,  $OTHERQTH and so on ...require you to tell the software this information.  Click on the LOG icon , upper right of your screen, and a simple log entry screen will appear.  If you enter in the other station's callsign, name, QTH and RST, you will be able to reference this information in your macros.



OTHER FAQ :

I have downloaded and installed Chip64. I am using Windows XP  on a HP Pentium 3 Gig machine. Any mouse activity onthe waterfall window causes the the waterfall
 to freeze. How do I correct this problem?

Well fellows, I have answerd this question now a few times already on several refelctors. Here again. If you use a Intel CPU with Hyperthreading and this is enabled in the Bios Setup, disable Hyperthread and all is ok- via  Chris HB9BDM



That's it, until a better help file comes along.  Feel free to email any additional items or suggestions for revisions.

73 de Andy K3UK
obrienaj@nestync.net.