27 May
2009
27 May
'09
3:14 p.m.
--- On Wed, 5/27/09, Philip Pemberton <classiccmp at philpem.me.uk> wrote:
You could probably reverse-engineer one with a
multimeter
in about 25 minutes. Remove all the jumpers, Set TURBO off,
find all the lines that are high, repeat with TURBO on. From
that you'll be able to figure out which pins are
always-high, and which depend on the state of the TURBO
input. Anything that stays low is a segment. If dealing with
a common-anode display, reverse "high" and "low".
Man, I remember setting these up... but it's been a while. When they were new, of
course, the cases came with little diagrams and instructions...
You should be able to figure it out with trial and error, it's really unlikely
something could blow up. Just fiddle with jumpers until you get it to say either the speed
of the computer, or "HI". Every one I've ever seen was set up like Philip
described, where each of the seven segments could be on normally, on with turbo, or on all
the time. Once you figure a couple of segments out the rest should be simple.
-Ian