IMSAI News?

From: Tim Shoppa <classiccmp_at_trailing-edge.com>
Date: Sun Jun 16 06:09:50 2002

> The power supply and its management was the least of your worries with their
> hardware. However, if your board required +/- 15, which was pretty easily
> regulated from the +/- 16, which was seldom limited to 16, you'd be in real
> trouble with the 12 volt bipolar supply.
>
> Further, I'd say, though it's not "new" nowadays, it was practiced only a
> short time in the life of the S-100. I think the deviation from the standard
> practices, not necessarily the "standard," was what led to its death,
> actually.

If I was going to do it today, I'd stick with the ~8V unregulated bus and
use a small buck switching regulator on each card. You get all the efficiency
of a switcher, and compatibility with older stuff.

With "Simple Switchers" from NatSemi (or equivalent from Motorola/Onsemi/
TI etc.) it's very easy to do. What's really good is that many of the
electronics distributors which let their inductor selection whither away
over the years now have excellent selections of inductors - some of which
they keep in stock! :-)

Tim.
Received on Sun Jun 16 2002 - 06:09:50 BST