If it's for the 64, it could be a cartridge like Action Replay or whatever was made for the 64. It usually has a pass-through on the expansion bus and a button to activate the cart. These carts were used to *freeze* the computer and allow you access to all the current memory to examine, change, or save entire blocks to disk. The logic chips were probably used to transfer control electrically from the Kernel to the code stored in the EPROM upon the push of the button. Jeff Salzman > >It's a white plastic cartridge with a 44-pin male card-edge connector and a >light blue plastic female passthru for the same type of connector. It has a >square black plastic button on top. It is (was) glued shut. Inside there is >an 24-pin EEPROM (88251A+ MM2716Q) with a Mitsubish Electric sticker >covering the window, a 14-pin IC (P234 DM7400N), and another 14-pin IC (EL >SALVADOR 1820-0328 7936 <Texas Instruments Logo> SN7402N). And two small >resistors and capacitors. On the circuitboard it says "NAVARONE (C)" and >next to the contacts where the little carbon pad on the underside of the >button makes contact, it says "TOP". >