Lost World ROM set numbers

Lost World uses "720-28" at U6; its other ROMs are numbered "729-xx", the latest revision being "729-33" for U1 and "729-48" for U2. Earlier versions carry other 729 numbers and must not be mixed with these.

Systems

• Bally MPU AS-2518-35

Games

• Lost World

Related tips

• Xenon keeps putting two balls in play after the battery died
• Rollover switch only registers with two diodes fitted: failing PIA at U10
• Why the MPU has ROM jumpers
• How the first-flash ROM test works
• After the test EPROM: refit the game ROM and count flashes
• ROM and EPROM types used on Bally MPUs
• Get the MPU booting before you change any ROM jumpers
• 9332 masked ROMs can be replaced by 2532 EPROMs as-is

Source: Repairing Bally Electronic Pinball Games from 1977 to 1985, Part Two, Clay Harrell (pinrepair.com)