[cctalk] Anyone used a M5C6847 in place of a MC6847?

I have a tube of them here, but they won't do anything in any VDG-based system here.  Wondering if it's just broken parts (I have no record of buying them, so must have been someone gifting them to me) or there's something I am missing: http://matthieu.benoit.free.fr/cross/data_sheets/M5C6847P-1.pdf -- Jim Brain brain(a)jbrain.com www.jbrain.com