I don't know if you folks are interested in my headaches, but here is my latest one. Working on an Atari Superman pinball board. ROM, RAM tests are good, board boots, issue is the feature lamps flicker when turned off. However I am getting something odd on address 1800-18FFh, it displays what appears to be the last data bit in the EPROM located at 3800-3FFFh. I plugged a different EPROM in and got its last data bit too. What is odd is the EPROM, when reading 1800h shows the Address lines all as low, but there is the tiniest pulse on /CE(pin 20). I've tried stretching it out, but it appears to be the smallest resolution of my Tek 100mhz, 2230 storage scope - which I am still learning how to use. At this point I figure it is a timing issue so will dig further, but I just thought is was most curious that it didn't matter which address location 1800-18FFh was chosen, I got what appears to be the last byte in the EPROM! I have no explanation on how that can happen. I will now test that by burning a couple of 2716 with only the last byte set, will try AA and 55 and see what happens... John :-#)# -- John's Jukes Ltd. 7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 Call (604)872-5757 (Pinballs, Jukes, Video Games) flippers.com "Old pinballers never die, they just flip out" _______________________________________________ Techtoolslist mailing list Techtoolslist@flippers.com https://pairlist7.pair.net/mailman/listinfo/techtoolslist FTP site is: ftp://ttl.arcadetech.org/TTL/Test_Equipment Archive site: http://seven.pairlist.net/pipermail/techtoolslist/