[BBC-Micro] Reversing the Tube ULA (destructively)

Pete Turnbull pete at dunnington.plus.com
Thu Oct 28 21:21:01 BST 2010

Pete Turnbull wrote:

> Nor will battery acid, which is not especially concentrated sulphuric acid.

Well, for your edification and delight, I tried an experiment a little 
earlier this evening.  A small amount of concentrated sulphuric acid on 
the top of an IC had no visible effect.  I also tried conc nitric (not 
the same as fuming nitric) and conc hydrochloric, and for good measure 
also a mixture of nitric and sulphuric (that's what you use to make 
guncotton and nitroglycerine) and /aqua regia/ (the 1:3 mixture of conc 
nitric and hydrochloric acids that is almost the only acid to dissolve 
gold).  None of them made the slightest impression on an IC package at 
room temperature.  The leads, yes.  The package, no.

Battery acid, btw, is about 30% sulphuric acid in water; commercial 
grade conc sulphuric, which is what I used, is about 95%.

Pete						Peter Turnbull
						Network Manager
						University of York

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