Need NS MM5740AAE/N keyboard encoder

I tried replacing the dead National Semoconductor MM5740AAE/N keyboard encoder chip on this Datanetics keyboard with an MM5740AAC/N thinking the C might just be some minor revision or whatnot and shouldn't make a difference. Well, I'm not sure if there is some greater thing wrong with this computer, but the keys don't map properly: Key => 1 2 3 4 5 6 7 8 9 0 : - Chr -> R F ^ A I U Y M C O S K D'oh! I can't find any data for this chip. Does anyone know if in fact the AAC is different from the AAN? Anyone got data? Anyone got a spare MM5740AAE/N? -- Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org [ Old computing resources for business || Buy/Sell/Trade Vintage Computers ] [ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]