Can you make those pics large enough to look at? They're thumbnail size images. -Shawn Brooke Clarke wrote: > Hi: > > I literally have a Black Box, see: > http://www.pacificsites.com/~brooke/BlkBox.shtml and have just finished > drawing a schematic for it using ExpressSCH (by Express PCB). There's a > mystery 16 pin SOIC that has had it's top painted white and hand > lettering of "12" larger letters and "298" smaller letters applied. The > "12" is the number engraved on the metal box (the only marking except > for a bar code label. I think the "298" is the ID for a pseudo random > code used for the spread spectrum transmission. The on-off modulating > signal comes from this mystery IC. The IC also blinks an LED. I don't > think it's a microprocessor because there are a couple of MC4060s and an > MC4051 all used to process a 26.868 kHz crystal down to a 5 second > transmit, 5 second pause signal that could have been put into a micro > controller. The date codes are for years near 1990. > > Since all the other chips are Motorola is there a Motorola (or maybe > not) IC that could be powered from a 9 Volt battery on pin 3 and has > ground on pin 11. It must have an internal high speed clock. > > Schematic available via email, color image of PCB via CD-ROM. > > Thanks for any help, > > Brooke Clarke, N6GCE > _______________________________________________ http://www.piclist.com View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist