On 9/2/09, Shoppa, Tim <tshoppa at wmata.com> wrote: Good call, but my digging with Google Images isn't turning up any visual matches. I'll see if I can't get some reasonable quality photos of the boards in case the style triggers any recognition. Indeed. We've had some Symmetricom products at the Pole. Fortunately, I only have to deal with them if they break, which is not often. Probably not pinball. The older one (7447-based) has all 6 digits jammed together for either a counter or hrs/min/sec with no colons. The newer ones are definitely 3 digits, gap, 2, smaller gap, 2, small gap, 2, even though one of them has 4 leading digits, only 3 are driven by the swath of MC14543s, so I'm going to go with DOY, hrs/min/sec for both of the newer units, which does suggest precision timekeeping devices. Unfortunately, the recent trend has been to LCD displays, so LEDs are somewhat older and hard to find info on. I was looking over the datasheet last night - the decode matrix is a lot like the 7447, except there's the possibility for injecting a square wave to directly drive LCDs. That's an odd feature. Thanks for the nudge towards that sort of gear. -ethan