Intersil Eprom 66S018? (IM6653?)

I have an old german PLC on the desk that I need to repair, it is an Eberle PLS511, build out of a 1Bit CPU build out of 4xxx CMOS Logic. I do have two slightly different units, one is equipped with 3 pcs 66S018 Eproms from Intersilm DC is 8319. I'm unable to find a datasheet for that device but I thin it is compatible to the old Intersil IM6653 1024x4 Bit Eprom to build the wordlength of 12 Bits out of 3 Roms.. There is a different memory Card equipped with 2 27C04, the jumpers are configured for a 2K Rom type..and it seems that the 27C064 ar only installed because of the CMOS Power consumption.. Can someone plase confirm that the 6653 is compatible to the 66S018 which may be a military variant? Is there a datasheet perferably including the description of the programming algorithm? Thanks in Advance, Holm -- Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe, Goethestrasse 15, 09569 Oederan, USt-Id: DE253710583 info at tsht.de Fax +49 37292 709779 Tel +49 37292 709778 Mobil: 0172 8790 741