[eip545B] part 3: few improvements about digits resolution

Thu, 15 Feb 2018 17:56:48 +0100

author
David Douard <david.douard@logilab.fr>
date
Thu, 15 Feb 2018 17:56:48 +0100
changeset 77
9ba7fe3d0a22
parent 76
aa1c62f79518
child 78
9e6170316dbe

[eip545B] part 3: few improvements about digits resolution

content/eip545b_3.rst file | annotate | diff | comparison | revisions
--- a/content/eip545b_3.rst	Fri Jan 26 23:32:39 2018 +0100
+++ b/content/eip545b_3.rst	Thu Feb 15 17:56:48 2018 +0100
@@ -54,7 +54,7 @@
 read the whole content of the RAM via GPIB.
 
 It's very slow, since I did not find a way using GPIB commands to read 2 memory
-addresses without quitting the TEST10 mode between to reads. And I had to add
+addresses without quitting the TEST10 mode between two reads. And I had to add
 several sleep() since the EIP is pretty slow to respond to GPIB commands. A
 complete dump of the 2ko RAM took somethin like 15 or 20 minutes.
 
@@ -133,8 +133,20 @@
 for the Frequency Offset, which I haven't done yet (I was waiting for a cheap
 EPROM eraser from eb, which just arrived).
 
-Now I also want to fix the initial resolution setup, which I haven't figured
-out yet.
+Concerning the resolution, some clue can be found just after the previous
+routine::
+
+   6125             LDX     #M005D                   ;8E 00 5D
+   6128             LDA     #$0D                     ;86 0D
+   612A             STA     $01,X                    ;A7 01
+   612C             LDA     #$05                     ;86 05
+   612E             STA     >M0045                   ;B7 00 45
+
+In which the value 0x0D is written at RAM address 0x005E (0x005D + 0x01 from
+the opcode ``STA $01,X``), and the value 0x05 is written at RAM address 0x0045,
+which we identified previously as a candidate for the digits resolution
+setting; pretty consistant with the 0x05 value written there. Not sure what the
+0x0D is used for at address 0x005E.
 
 
 The sensitivity problem
@@ -163,7 +175,7 @@
 
 On the bottom side, we can see the YIG spheres and the coupling loops:
 
-.. image:: {filename}images/eip545b/yig_bottomn.jpg
+.. image:: {filename}images/eip545b/yig_bottom.jpg
    :alt: Top view of the YIG filter
 
 So this filter consists in a 2 stage bandpass filter (with input and output
@@ -193,8 +205,8 @@
 HighPrecision), we'll see if it works. I hope it's a 127MHz version, otherwise
 I'll have to replace the YIG filter (A201) on my A203 unit with this one.
 
-By the way, for thoses interested, I found these 2 documents interesting to
-begin to understand how a YIG oscillator and a YIG filter works:
+By the way, for thoses interested, I found these 2 simple documents interesting
+to begin to understand how a YIG oscillator and a YIG filter works:
 
 - `YIG TUNED OSCILLATORS`_
 - `YIG TUNED FILTERS`_

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