MOS MCS2529 math chip

[Jules Richardson via cctalk]

Anyone got pinout/spec information for a MOS MCS2529? In particular, I'm 
curious about operating voltage. I acquired a Melcor SC-635 calculator 
yesterday and there seems to be some uncertainty about the output voltage 
of its (rechargeable) battery pack; some places say 2.4V, i.e. the pack is 
a pair of 1.2V cells, but others say 9V.

2.4V seems a little low to me for typical logic, but on the other hand I've 
seen a period ad which says that the external PSU was 9V - and so the 
rechargeable battery must have been somewhat less than that.

cheers

Jules