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                                    AA_908 VERSION HISTORY
                                          11/28/2005
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VERSION 5.0d (11/28/2005)
1) Support for DDS-60 Daughtercard:
   Changed to using AD9851 DDS with 30 MHz ref clock (using 6xPLL setting in MSB control word of AD9851)
   Added 'AD9850' variable in EEPROM page 1 to indicate which DDS chip selected (9850=1, 9851=0)
   Added new Config command to allow selection of "30 MHz DDS" or "60 MHz DDS";
   Changes for AD9851 chip in Drivers.asm (DDS_init for turning on 6x PLL), and
   in Mode.asm (Mult to use correct digit scaling values, and in BCD_Inc to handle max display)
2) KA7OEI user interface fixes/improvements: 
   Step shows current setting;  Start, End, and main display show previously-used frequencies;  
   StartFreq/EndFreq display no longer corrupted; Band, Mode and Config selection lists start from 
   previous setting; Last-used Mode is re-entered when exiting Config or Band menus instead of 
   always going back to Impedance.
3) Fixed Scan routine to include first sample in data transmission to terminal.
4) Changed select method in setting start/end freq in Config to press of Dial (instead of pressing <Config>)
5) Changed initial display of start/end freq (in Config) to be current setting (not always 10 MHz)
6) Tone varies with changes in SWR again, even when the dial is not being moved. (Facilitates changing antenna 
   while listening to lower SWR.)

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VERSION 4.3a (4/21/2005)
1) Added LCD Backlight control.  (Optionally uses different LCD and new transistor to board.)
2) Restructured the source code to provide integration with AF908 module. (Compile time switches.)

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VERSION 4.2b (4/13/2005)
1) Fixed tone to properly swing to min freq during Scan ... and stay there when scan complete.
2) Display reactance sign only when Sleep PB is pressed.  This may help create more stable X readings.
3) Added loop to Config selection of Battery display (allows monitoring batt voltage during charge).
4) Removed a lot of unnecessary code and comments from the SEEPROM testing days.

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VERSION 4.2a (3/28/2005)
1) Found another way to invoke entry to HCmon for the Software Load function in Config, thus
   eliminating the occasional halted downloading and need for using the "P3 jumper method" of loading.
2) Corrected the upper band limit for 12m operation.

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VERSION 4.2 (3/24/2005)
1) Found the bug causing the "SWR>10" condition.  Actually only happened with narrow resonances   
   when the AA908 reaches out past the resonance to determine reactance sign.  During that    
   condition, the SWR display got "out of sync" with the foreground (dial turning) vs. background    
   (dial still) computations and the ">10" display remained when coming back to the current    
   frequency state.
2) Ensures max setting of 30 MHz for specifying End Freq in Config.

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VERSION 4.1e (3/4/2005)
Temporary disable "jsr Disp_Sign" in ISR until I fix the "constant SWR>10" condition

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VERSION 4.1 (2/27/2005) Production
This version supports the "reactance sign feature" and Link908

1) Corrected stack bugs in Get_Dial_Selection and Get_YN routines
2) Corrected portA bug in LCD driver
3) Merged WARC Band sppt and raw Link908 data transmit to mainline code
4) Added Config options for scan data (no save, send to PC, send to SEEPROM)
5) Added placeholders for SEEPROM code (search .LST file for "INSERT SEEPROM USAGE HERE")
6) Added Link908 interface
7) Band selection increased to include WARC bands.  (M. Hasenfratz, WA6FXT).
8) Table-driven method used for selecting bands.
9) Changed reactance sign measurement technique to check up or down 3 MHz, depending
   on where the current frequency point is in the band (20 MHz)

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VERSION 4.0c (12/5/2005) Production
1) Changed pushbutton user interface to be consistent with others (press Mode to 
    see sub-menu of available modes: Impedance, Capacitance, Inductance, VFO).
2) Calibration point changed to 10 MHz.

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VERSION 4.0 (11/15/2004)
This newest software should be used once the Service Pack has been installed.  It depends on proper channel gain with the ERA-3 amp on the DDS card, and with R19,R24,R29,R51 = 71.5K.

1) Changed to using ERA-3 with different gain resistors.  Getting rid of MAV-11 solved
high-end signal level rolloff.

2) Changed to "back_to_basics" simplified calibration, adjusting Vr to make SWR=5.4
with 270-ohm load.  Best performing results ever!!

3) Added LCD backlight control circuit (and software timers, Setup menus, etc.)

4) Fixed bug in calculating R (was improperly scaling large denominator)

5) Started measuring and adjusting for A/D offset voltages.  Improved accuracy a bit.

6) Now handling remainder of correction factor generation and use.  Yields best results yet!

7) Fixed cursor adjust too far to left.

8) Straightened out Lite control and EEPROM save/restore

9) Moved cal data to EEPROM Page 1.

10) Fixed power-on pushbutton so timing not critical on release.

11) Added "Stopped" display at powerdown.

12) Made the Default Settings option more sensible and usable.

13) Determine & display reactance sign.  (I'm still not happy with this and more changes will come.)

14)  Reactance Sign Determination -- I diddle the freq (by 1 MHz!) when the 
instrument is in Impedance Mode, and when the dial is at rest.  You can see 
this on a scope connected to the load.  Kind of interesting, actually.

15)  L & C Measurements -- Pressing Mode will allow you to select among the different
Modes available for the instrument: Impedance (default), Capacitance, Inductance and VFO.

16)  VFO Mode -- I added a fourth mode called "VFO" which just outputs the 
test signal, without diddling, yielding a signal suitable for external use.

17) All references to that experimental power control feature have been 
removed, so the Micro908 will not randomly go into "stopped" mode, and the 
mysterious interaction with the Sleep pushbutton is gone. Whew! :-)

18) Tone operation is cleaned up a little bit more ... should fix the 
"metronome" effect that some of you guys have noted.

19) The strange readings of "0 +j50" below 8 MHz with 50-ohm load resistor is 
cleared up.  (In some cases, the no-load Vr offset voltage was greater than 
the Vr reading, which was near zero with a perfect match load, resulting in 
a negative corrected sample reading of Sample - Offset  ... not cool.  This 
only showed up after I sampled numerous units and saw what some of you guys 
were noting.)

20) User interface change to allow dropping right into Impedance mode upon start-up.

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VERSION 3k5 (9/2/2004): "First Production Release"

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I will keep working on improvements, as always, and keep everyone posted. 
Thanks for everyone's support.

Let us know how this new release works for you!

73, George Heron, N2APB
      n2apb@amqrp.org
      www.amqrp.org/kits/micro908


