As most of you are likely aware, the 9010A Service Manual only includes the Firmware (ROM) signatures for versions 1A, 2A, and 2B, and the most recent (and in my experience, most common) version 3A is not included. For those of you who want to repair a 9010a using another 9010a, attached is the updated Signature table from the Service Manual with a column for the 3A version (thanks to Tim for providing this). Note that the signatures in this table for a piggy-back, 6 ROM version of the 9010a HW, but that most people with Firmware 3A have the newer, non-piggy-back, 3 ROM version, in which case the signatures are: Addressable Device Signature version 3A Address (HEX) U9 1D1F 0000 - 3FFF U19 2BC4 4000 - 7FFF U21 270E 8000 - BFFF Hope this helps someone. grant.. _______________________________________________ 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/