{{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-01A: was dipped in hot acid for a few hours (contrast to minutes for the
  other chips) to take out a lot of the epoxy.  I haven't done any further
  processing on it, looks like this if you are curious (picture below)  I may be
  able to mechanically lap it to expose the chip surface but this will be somewhat
  labor intensive (same with above if I got another copy)...
"""


====== Package ======

{{:mcmaster:commodore:ghu-01a:package_top.jpg?300}}
{{:mcmaster:commodore:ghu-01a:package_bottom.jpg?300}}

After soaking in acid for a few hours...

{{:mcmaster:commodore:ghu-01a:decap2.jpg?300}}
{{:mcmaster:commodore:ghu-01a:decap4.jpg?300}}

Label:
  GHU-01A
  ESR-Y
  7623


====== Die ======

Not exposed


====== References ======

http://www.vintage-technology.info/pages/calculators/commodore/comsr8120.htm