Ways to fit EPROMs at U2/U3

A 2332 is not pin-compatible with a 2532 or 2732, so either fit a plug-in U2/U3 adapter, or rework the board (2532/2732 need an extra logic gate), or use one 2764 holding both images in the U3 socket, which the guide finds easiest. The two images join into one 2764 file with a binary copy, U2 first then U3 (a DOS binary copy of the two files into one).

Systems

• Gottlieb System 80
• Gottlieb System 80A

Related tips

• Which System 80 test EPROM image to use
• Bench setup for the System 80 test EPROM
• Testing the DIP switch inputs with the test EPROM
• Fitting the 2532 test EPROM at U3 on a board without a piggyback
• System 80 test EPROM LED flash codes
• How a 2332 rules ROM differs from a 2532 EPROM
• Test EPROM stalls at the switch matrix RIOT (U4)
• Test EPROM 2: game PROM socket test fails

Source: Repairing & Upgrading Gottlieb System 80 Pinballs from 1980 to 1989, Part Two, Clay Harrell (pinrepair.com)