Updated oscillator section.

Author: jasonsbeer

AssemblyNotes.md

@@ -16,9 +16,15 @@ Notes:
 
 The best source of parts for this project is a dead or dying Amiga 2000 board. Otherwise, many of the Amiga legacy IC's and parts can be obatined from various internet suppliers. Unfortunately, Buster (MOS 5721) can be difficult to find. Beware the original Buster revision (318075-01) has a buffering error and cannot be used without a "Buster Tower". Be sure to use the one specifically listed in Table [A1](#table-a1-legacy-parts-required) or build a replacement option.
 
+## Oscillator
 You will need an oscillator installed at X1 or X2 to generate a clock signal. You can find 5V TTL oscillators from various legacy suppliers in the 14-DIP format. In the event you cannot find one, you can use a 3.3V CMOS oscillator of the same frequency in position X2. See Table [A1](#table-a1-legacy-parts-required). Do not populate both X1 and X2.
 
-**Note on CMOS oscillator:** 3.3v CMOS logic is compatible with in-spec TTL logic. My test board worked well with a 3.3v CMOS oscillator. All clock signals from Agnus are correct on my test machine. I would still recommend using like-for-like logic, if possible. Using the 3.3v CMOS oscillator should only be considered if a TTL oscillator cannot be reasonably obtained. 
+**Note on China sourced oscillators:** 
+There are reports that some new 14-DIP oscillators sourced from China have an output enable signal on pin 1. Original 14-DIP oscillators have no connection on pin 1, thus pin 1 of X1 is not connected on the Amiga 2000 EATX board. If you have one of these oscillators and are not getting oscillations, you should try pulling pin 1 to logic high by connecting it to +5V. Pin 14 of X1 is a good place to do this. If that corrects the issue, you can bodge a wire between pin 1 and pin 14 of X1. Note that the reported oscillators have an "@" instead of dot marking pin 1.
+
+<img src="/Images/Oscillator.jpg" width="250">
+
+**Note on X2 CMOS oscillator:** 3.3v CMOS logic is compatible with in-spec TTL logic. My test board worked well with a 3.3v CMOS oscillator. All clock signals from Agnus are correct on my test machine. I would still recommend using like-for-like logic, if possible. Using the 3.3v CMOS oscillator should only be considered if a TTL oscillator cannot be reasonably obtained. 
 
 ## Configuring the Agnus Jumpers
 The revision 2.x board supports multiple Agnus revisions. See Table [A2](#table-a2-agnus-parts-supported) for a list of part numbers supported. Not all the listed part numbers have been directly tested. Reviewing related literature suggests all the listed parts numbers *should* work. However, <b>until each specific part number is tested, there is no guarantee any particular Agnus will work</b>, even if listed. Table [A2](#table-a2-agnus-parts-supported) indicates the status of each part number. If you test a new Agnus part number, please place a new post in the issues tab so the table can be updated.