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--- mcmaster:commodore:ghu-03a [2013/07/31 05:34] – created mcmaster
+++ mcmaster:commodore:ghu-03a [2021/05/28 02:34] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
-{{tag>collection_mcmaster vendor_commodore year_unknown}}
+{{tag>collection_mcmaster vendor_commodore year_unknown foundry_unknown tech_unknown}}
+“found in several calculators but this specific one was from an SR7949D (only sold in the UK)”
+"""
+  The two GHU chips are made of a (high silicate?) epoxy I've never seen before.
+  The silicate content makes chemically decapping them extremely difficult.
+  Although I can get acid to penetrate a few mm to remove the epoxy it leaves
+  a strong skeleton behind that so far I've only been able to remove mechanically.
+  So this is where they stand:
+  GHU-03A: this chip has sustained enough damage now that I have to declare it "dead".
+  We should get another one if its worth imaging.  I tried gradually more aggressive
+  techniques to get the encapsulant off.  The last ditch effort was ultrasound which
+  could work to knock the last layer off but is dangerous because on imperfect chips
+  because it can cause a chip to crack...the latter happened.  I'm saving the remains
+  just in case but if you *really* want this chip imaged we should get another one...
+  assuming I can figure out a way to decap it
+"""
-From "Commodore SR8120 (aka SR8120D)"?
 ====== Package ======
-{{gallery>:mcmaster:commodore:ghu-03a:package_top.jpg?300}}
+{{:mcmaster:commodore:ghu-03a:package_top.jpg?300}}
-{{gallery>:mcmaster:commodore:ghu-03a:package_bottom.jpg?300}}
+{{:mcmaster:commodore:ghu-03a:package_bottom.jpg?300}}
-{{gallery>:mcmaster:commodore:ghu-03a:decap3.jpg?300}}
+{{:mcmaster:commodore:ghu-03a:decap3.jpg?300}}
-{{gallery>:mcmaster:commodore:ghu-03a:decap4.jpg?300}}
+{{:mcmaster:commodore:ghu-03a:decap4.jpg?300}}
+Label:
+  GHU-03A
 ====== Die ======
-{{gallery>:mcmaster:commodore:ghu-03a:shard1_overview_mit2x.jpg?300}}
+{{:mcmaster:commodore:ghu-03a:shard1_overview_mit2x.jpg?300}}
-{{gallery>:mcmaster:commodore:ghu-03a:shard1_sample_mit20x.jpg?300}}
+{{:mcmaster:commodore:ghu-03a:shard1_sample_mit20x.jpg?300}}
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 http://www.vintage-technology.info/pages/calculators/commodore/comsr8120.htm