Well I've got a Fluke 90 (Z80) unit and started testing it out. It claims to have "cycle stealing" abilities to test while the test board is running. I am working with Pac-Man boards right now. I can do ROM checksums in circuit as the game runs. How do I do RAM test of the 2114s at $4000-$47FF & $4C00-$4FFF? These are behind address buffers and the Sync Buss Controller. It appears that the RAM is only available on 2H cycles from the clock. Is there any way to test the RAM in circuit, using the Fluke90. I think I could build a jumper plug for the Sync Buss Controller & enable the Data buffer & address buffers manually but then I'm starting to defeat the purpose of in circuit testers. Thanks, Kev To UNSUBSCRIBE from techtoolslist, send a message with "UNSUBSCRIBE" in the message body to: techtoolslist-request@flippers.com. Please direct other questions, comments, or problems to jrr@flippers.com.