Am 24.01.2013 22:40, schrieb Christian Dirks: > The IEEE bus handshake lines are controlled by the 6525 at U2, > only the data lines are controlled by the 6526 at U1. > So U2 may be bad. > > I did some tests on a working CBM610: > It will start up with the PLA removed, but it will not be useable, > since there will be no DRAM accessible. > It will start up with the 6526 removed. (No IEEE bus) > It will start up with the 6551 removed. (No RS-232) > It will start up with the SID removed. (No sound) > It will start up with the 6845 removed. (No video) > It will start up with the char-rom removed. (Video not readable) > It will start up to the TIM monitor with the Basic ROMs removed. > It will NOT start up with the 6525 at U28 removed. > It SHOULD start up with the 6525 at U2 removed with no IEEE bus. Since > this one is soldered in, I did not test it. After testing this with a CBM710, I am to correct myself: It will NOT start up with the 6525 at U2 removed. > Without the Basic ROMs and PLA, TIM will work fine in bank 15. CTRL-G > will ring the bell. The IEEE bus will work. (.L "$",08) Christian -- Christian Dirks Toast_r@Idealine.info Message was sent through the cbm-hackers mailing listReceived on 2013-01-26 23:00:02
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