This is for a '91. As shown in the inset, the PROM (doubtless, your main reason for being here!) is secured by a retaining clip. I pried it off at the bottom edge of the chip, but slots are also provided on top of the clip for inserting a small flat blade screwdriver to pry the clip off. Whatever; it's easy.
Once the clip is off, you can pry the PROM out of its socket, if that's your mission. Remember: Use good anti-static procedures and check carefully for bent pins (they can curl under the chip and hide themselves very cleverly!) The notch on the PROM faces toward the outside of the board,
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