reverse-engineering power

From: Doug Yowza <yowza_at_yowza.com>
Date: Sun May 17 19:15:55 1998

On Sun, 17 May 1998, Tony Duell wrote:

> > > first: hook up the voltmeter to the 74xxxx chip for 5v and ground.
> >
> > I'm reading around 3.2V, which would make sense for a laptop.
>
> Unless you know it's a 3.3V logic family, then I would suspect that it
> too low. What is the complete number on the chip you're testing?

Most newer laptops use lower-voltage logic to conserve battery power.
This one was designed to demo a couple of highly-integrated chips, so the
only 74-series chips are some 74AC244 and 74ACT244 buffers. I tested one
of the "AC" chips.

-- Doug
Received on Sun May 17 1998 - 19:15:55 BST