Re: repairing common woodstock problem - hp 22 Message #7 Posted by Eric Smith on 28 Jan 2004, 5:54 p.m., in response to message #6 by Albert
And those are just about the only ones. NONE of the ICs in an actual Woodstock calculator is standard, nor are any of the ICs in the Classic, Spice, or Voyager series. The 67 and the Topcat models are the only HP calculators I can think of made before the mid-1980s that contained any standard ICs at all, and they didn't have many even in those.
The HP-85 was AFAIK the first Corvallis division product to use industry standard RAM chips. The HP-75 was the first handheld to do so, and the HP-28S was the first handheld calculator to do so.
I've inspected the innards of every released model of HP handheld calculator and almost every desktop (including some unreleased ones). I've done a fair amount of reverse engineering of how the custom circuits work. I'm not just making this stuff up.
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