GAL16V8 as a modern substitute for a 7447?
Henk Gooijen
henk.gooijen at hotmail.com
Sat Dec 8 12:08:29 CST 2007
Ethan wrote
> Has anyone here worked with or ever plotted silently to create a moderish
> 7-segment decoder/driver from a GAL16V8? I'm working on a project made
> from classic parts, and am trying to reduce part count rather aggresively,
> since I'm going to hand-wire it.
I have build a small clock, and did not want to do much wiring,
so I used 73LS390 and those fancy HP "7-segment" displays
that display the numbers in a series of dots. Old HP counters have them.
I love those displays. Also, those displays have a 4-bit latch and "7447"
incorporated. They have 4 (or 5, I can't remember) pins on the lower
side and ditto on the upper side. 4 pins are obviously for the BCD code,
2 pins are for +5V power supply, one pin is LATCH, one pin is BLANK.
The dimensioning is such that they can be "stacked", put neatly next to
each other. As these displays have the 7-segment decoder and the BCD latch
inside, it made the wiring/soldering quite easy, and you get a "cool display" :-)
Henk
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