Datasheet of an unknown IC
The last line ("1020B-44") suggests that this is an Actel ACT 1 nonvolatile FPGA (A1020B) in a PLCC-44 package. A number of the pin assignments match up perfectly, and the manual that you've got mentions the FPGA in a few places.

Here's the datasheet: http://www.actel.com/documents/ACT1_DS.pdf