April 9, 1992 As luck would have it, KCT510 contained a potentially disastrous bug. If, during an active pass, the mode was switched from real time to tabled and an attempt was make to load the table, a math error occurred that caused the program to crash. Unfortunately, if the rotors were moving when the program crashed, nothing short of turning off the rotors would prevent them from continuing to the mechanical stops (whatever they may be). Brooks points out in his KCT/T manual that if the rotors are activated and the program is killed (such as a "warm restart" would do), the rotors will continue to turn since the controlling program has died. The safest approach is to make sure your antenna system can handle full excursions of the rotors to their mechanical stops. Short of that, if the KCT/T (i.e., your couputer) dies for any reason, TURN OFF THE POWER TO THE ROTORS IMMEDIATELY. I believe this version (KCT511) has all the bugs out, but checking all the various combinations of functions and transitions between modes for all possible conditions is difficult and time consuming, to say the least. Incorporating functions that were never intended has resulted in some pretty complicated and convoluted code. I've taken it about as far as it will go without a major rewrite, and I think I'll save that energy for other projects. I am very active on UO-22 and Internet, so those are the two best ways to contact me. I check CI$ occasionally, and after being spoiled by 9600 baud, rarely get on AO-16 and LU-19 anymore. March 6, 1992 This package contains all the contents of the original (KCT500) plus the new AMSAT Journal Article describing the new features (KCT510.TXT). The software interrupt used by OrbitDRV to pass the range rate is INT 64H. If you use other software that also attempts to use INT 64H, you may have a conflict and strange operation may result. Try to isolate the offending program by removing one program at a time. I have my KCT/T and Quiktrak/InstantTrack running on a separate IBM PC (with coprocessor) to avoid the problems associated with trying to run TSRs and CPU intensive applications and handle PB and PG (or NET) with 9600 baud traffic at the same time. November 1, 1991 This package should contain the following: KCT500.TXT (AMSAT Journal Article) TUNER.COM DRV.COM OSC.COM MOVENOW.COM BBSROTOR.COM DEPH.COM README.TXT HARDWARE MODIFICATIONS Read the instructions in the AMSAT Journal article thoroughly and make sure you have the tools to make the necessary mods. You can easily mangle your KCT card if the mods are not done carefully. I tried to make them as simple as possible and still maintain the original functionality of the card, so the original software can be run with no problems. The only change that should be necessary is replacing the "modified" 74LS126 (U7) with a new 74LS126, which is easy if a socket is installed. SOFTWARE INSTALLATION First, BE SURE TO SAVE A COPY of your original, unmodified KCT files so that when the inevitable happens, you can at least get back to square one. I have modified the DRV, OSC and TUNER "COM" files, and the others check for the correct version, so you must use ALL of the files in this package. Simply replace your current COM files with the COM files I have supplied, make sure your time and keps are as accurate as possible and reboot your system. The changes in the DRV and OSC files are minimal and the RAM requirements are about the same as the original versions. The TUNER file is much larger to accommodate the new code and a large buffer for the tabled pass functions. At least 80K of free RAM is required for this version to run. Anytime mods are made to a product as complicated as the KCT (especially by someone other than the original author), the chance for bugs is great. I have used the modified KCT for about a month without any problems, but who knows what lurks during the next pass! I would appreciate bug reports, but depending on (professional) work load, family activities, etc. I cannot guarantee fast (if any) response. Caveat emptor, and what do you want for free? I would also appreciate positive feedback so I know other people are using these mods. Make sure the RIO switch is set properly in the DRV command line! You MUST specify it in the command line and it should be "0" for all cards except the LLG02 rev. "B", which should be "1". Weird things will happen to your rotors if it isn't correct. If the rotors don't work properly try switching to the opposite RIO switch (i.e., if 1, try 0....if 0, try 1). BUGS Occasionally (very rare on fast machines, more often on slower machines) the time will freeze on the Tuner Pop-Up when it is invoked using the selected hot key. Most function keys from the active window still seem to work, but since (apparently) the clock interrupt has been masked for some reason, KCT doesn't do much tracking or tuning. This problem exists in the original 2.34 version of the software and it still exists in my modified version. The only solution at this point (since this is a very tough bug to track down) is to check the time and verify it is changing each second whenever the Tuner Pop-Up is invoked. If the time is frozen, simply press and invoke the Tuner Pop-Up with the hot key sequence again and everything should be fine. Leaving the Pop-Up with the time frozen causes some real strange things to happen after a few minutes, so exit the window with the key when the frozen time condition exists. HINTS ON USING THE PK232 AND THE MICROSAT SOFTWARE I have found several idiosyncrasies involving the PK232 and the Microsat software. I had problems getting the PK232 into a "clean" KISS mode after using other software (particularly after using Pakratt). The solution that seems to work every time is to turn off the PK232 for a few seconds, turn the PK232 on, issue the required number of "*"s for the autobaud routine to work, issue the reset command and the same number of "*"s again followed by the restart command (using a dumb terminal program such as YAPP that doesn't cause the PK232 to enter host mode), and then run PB or PG. Also, turn the PSK modem off when starting PG or PB or when switching between PG and PB. Apparently the stream of data from the modem during program initialization corrupts something and makes connecting to the Microsats very difficult and sporadic. Also checkout David Medley's article on the PK232 and Microsat software in the May 1991 AMSAT Journal. He has more detailed information on making the PK232 work correctly. In my own installation, I seem to have no problem starting either PB or PG after the above initialization and I also have no problem switching directly between PB and PG if the PSK modem is turned off. I am using the 901221m version of PB, the 910207r version of PG and the 31OCT89 release of PK232 firmware. FINAL COMMENTS I encourage experimentation with the parameters that the user has some control over (such as the radio tuning step size). Different combinations of parameters may work better for other combinations of modems, tncs, etc. Let me know what works best for you. HAVE FUN and see you on the birds! JOE BARGER N6KK 2009 Harkness St. Manhattan Beach, CA 90266: internet: barger@aerospace.aero.org satellite: AO-16, LU-19, FO-20 bbs: N6KK @ WB6YMH compuserve: 71560,2514 (checked occasionally)