Dave McGuire wrote:
And actual HP signature multimeters show up everywhere, and tend to be
cheap.
Of course, if they're not cheap enough, you can always build a signature
analyser out of a couple of LSTTL chips. If memory serves, the core of the HP
5004 analyser is an LS86 XOR, a pair of LS164 shift registers, and some logic
to drive the displays. If you can live with having to do some hex ->
signature-code conversions (it's basically a quick substitution of the letters
from one to the other), then four TIL311s will work
nicely as a display. If I
didn't have any TIL311s to hand, I'd probably
program an EPROM to do the
conversion, and use a couple of 7-segment LED displays.
Rik's right though, the May 1977 HPJ tells you just about all you really need
to know to clone a HP signature analyser...
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/